Rolling mill and rolling method

Abstract

The present invention comprises: a plurality of hydraulic cylinders that include drive-side shift cylinders 715C, 715D and operation-side shift cylinders 715A, 715B that are configured to apply force to an upper work roll 710 in the axial direction thereof; and a hydraulic circuit that is configured to send hydraulic fluid to the plurality of hydraulic cylinders to move the drive-side shift cylinders 715C, 715D and the operation-side shift cylinders 715A, 715B in the axial direction and hold the position of the upper work roll 710 in the axial direction. The hydraulic circuit is configured such that, when only either the drive-side shift cylinders 715C, 715D or the operation-side shift cylinders 715A, 715B are applying force to the upper work roll 710 in the axial direction due to external force on the upper work roll 710 after the hydraulic circuit has held the position of the upper work roll 710 in the axial direction, the other hydraulic cylinders move in the opposite direction.

Description

Rolling mill and rolling method

[0001] The present invention relates to a rolling mill and a rolling method.

[0002] Patent Document 1 describes a rolling mill comprising an upper work roll, radial bearings and thrust bearings provided on the operating side and drive side of the upper work roll to support the upper work roll, a shift cylinder provided on the operating side of the upper work roll for applying force to the thrust bearing in both the operating side and drive side directions, and a shift cylinder provided on the drive side of the upper work roll for applying force to the radial bearing in both the operating side and drive side directions, and the shift cylinders each apply force to the radial bearing and thrust bearing in the same direction when the upper work roll is not shifting axially at least during rolling.

[0003] International Publication No. 2022 / 030004

[0004] Patent Document 1 discloses a structure in which rolls are shifted on both the driving side and the operating side.

[0005] The direction of the thrust force acting on the rolls of a rolling mill may switch between the drive side and the operating side due to changes in conditions such as rotation. In this case, after the roll position is set, a thrust force in the opposite direction acts, causing the roll, or more specifically, the members supporting the roll, to temporarily move away from the drive side and operating side arms that support the thrust force. As a result, the positions of the arms on both sides must be adjusted again to support the thrust force of the roll.

[0006] However, if there is uneven axial play (gap) in the support part that applies axial force to the roll, the thrust force may be supported by only one arm.

[0007] If one arm cannot support the load, the pressure in the piping connected to the hydraulic cylinder that moves the arm will exceed the relief valve set pressure (maximum pressure), and hydraulic oil will escape from the relief valve, causing the other arm to move as well.However, because the relief valve set pressure is high, it became clear through investigations that this could lead to a reduction in the lifespan of peripheral equipment such as bearings that are subject to the load.

[0008] It has become clear that this is not limited to the above-mentioned cases, and that when the roll expands due to the heat of the heated metal band, uneven play in the axial direction can occur, which can lead to problems similar to those described above.

[0009] An object of the present invention is to provide a rolling mill and a rolling method that can improve the life of roll support parts such as bearings on both sides of a roll without creating excessive pressure inside the piping to which a hydraulic cylinder is connected.

[0010] The present invention includes multiple means for solving the above-mentioned problems. One example of such a means includes a mill roll, a plurality of hydraulic cylinders including a drive-side hydraulic cylinder provided on the drive side of the mill roll configured to apply an axial force to the mill roll, and an operating-side hydraulic cylinder provided on the operating side of the mill roll configured to apply the axial force, and a hydraulic circuit configured to supply hydraulic oil to the plurality of hydraulic cylinders, causing the drive-side hydraulic cylinder and the operating-side hydraulic cylinder to move in the axial direction and maintaining the axial position of the mill roll, wherein the hydraulic circuit is configured such that after the hydraulic circuit has maintained the axial position of the mill roll, if an external force received by the mill roll causes only one of the drive-side hydraulic cylinder or the operating-side hydraulic cylinder to apply the axial force to the mill roll, the other of the drive-side hydraulic cylinder or the operating-side hydraulic cylinder will move in the direction opposite to the one hydraulic cylinder.

[0011] According to the present invention, it is possible to improve the life of the roll support parts such as bearings on both sides of the roll without creating excessive pressure in the piping connected to the hydraulic cylinder. Objects, configurations and effects other than those described above will become clear from the following description of the embodiments.

[0012] FIG. 1 is a diagram showing an outline of rolling equipment including a rolling mill of Example 1. FIG. 2 is a front view illustrating an outline of the rolling mill of Example 1. FIG. 3 is a view taken along the arrows A-A' in FIG. 2. FIG. 4 is a schematic diagram illustrating the problem to be solved by the present invention. FIG. 5 is a schematic diagram illustrating the problem to be solved by the present invention. FIG. 6 is a plan view illustrating details of the upper work roll portion of the rolling mill of Example 1. FIG. 7 is a plan view illustrating details of the upper work roll portion of the rolling mill of Example 1. FIG. 8 is a plan view illustrating details of the upper work roll portion of the rolling mill of Example 1. FIG. 9 is a plan view illustrating details of the upper work roll portion of the rolling mill of Example 1. FIG. 10 is a plan view illustrating details of the upper work roll portion of a rolling mill of a modified example of Example 1. FIG. 11 is a plan view illustrating details of the upper work roll portion of the rolling mill of Example 2. FIG. 12 is a plan view illustrating details of the upper work roll portion of the rolling mill of Example 3. FIG. 13 is a plan view illustrating details of the upper work roll portion of the rolling mill of Example 3. FIG. 14 is a plan view illustrating details of the upper work roll portion of the rolling mill of Example 4.

[0013] Hereinafter, an embodiment of the rolling mill and rolling method of the present invention will be described with reference to the drawings.

[0014] In the drawings used in this specification, identical or corresponding components are denoted by the same or similar reference numerals, and repeated description of these components may be omitted.

[0015] Furthermore, in this specification, the thrust resistance force refers to the force in the roll axis direction acting on each roll and its bearing housing of the rolling mill during rolling or when shifting during rolling, and refers to the force acting on the device that supports that force, and has the same meaning as the thrust force. The thrust reaction force refers to the force generated by the device that supports the thrust resistance force, and refers to a force that is opposite in direction to the thrust resistance force and has the same magnitude.

[0016] <Embodiment 1> A rolling mill and a rolling method according to embodiment 1 of the present invention will be described with reference to Figs.

[0017] First, an outline of a rolling facility equipped with the rolling mill of this embodiment will be described with reference to Figures 1 to 3. Figure 1 is a diagram showing an outline of the rolling facility equipped with the rolling mill of this embodiment 1, Figure 2 is a front view explaining the outline of the rolling mill, and Figure 3 is a view taken along the line A-A' in Figure 2.

[0018] As shown in Figure 1, the rolling equipment 1 has multiple rolling mills that hot roll a rolled material 5 into strips, and has a control device 80 and five stands, namely, a first stand 30, a second stand 40, a third stand 50, a fourth stand 60, and a fifth stand 70 from the entrance side of the rolled material 5.

[0019] Of these, each of the first stand 30, second stand 40, third stand 50, fourth stand 60, and fifth stand 70 and the part of the control device 80 that controls each stand correspond to the rolling mill as defined in the present invention.

[0020] The rolling equipment 1 is not limited to a multiple-stand equipment such as the five-stand equipment shown in Fig. 1, but may be a single-stand equipment. In addition, since the temperature of the rolled material during rolling is not limited, the rolling equipment may be a cold rolling equipment.

[0021] Next, a part of the outline of the rolling mill of the present invention will be explained using Fig. 2. Note that in Fig. 2 and subsequent figures, the fifth stand 70 shown in Fig. 1 will be explained as an example, but the rolling mill of the present invention can be applied to any of the first stand 30, second stand 40, third stand 50, and fourth stand 60 shown in Fig. 1.

[0022] In FIG. 2, the fifth stand 70 which is the rolling mill of this embodiment is a six-stage rolling mill for rolling the strip 5, and has a housing 700, a control device 80, and a hydraulic device 90.

[0023] The housing 700 includes an upper work roll 710, a lower work roll 711, an upper intermediate roll 720, and a lower intermediate roll 721 that contact and support the upper work roll 710 and the lower work roll 711, respectively. The housing 700 also includes an upper backup roll 730 and a lower backup roll 731 that contact and support the upper intermediate roll 720 and the lower intermediate roll 721, respectively.

[0024] Of these, the "mill roll" in the present invention corresponds to any of the above-mentioned upper work roll 710, lower work roll 711, upper intermediate roll 720, lower intermediate roll 721, upper backup roll 730, and lower backup roll 731. In the case of a rolling mill that does not have intermediate rolls, such as the first stand 30 or the second stand 40, the upper and lower work rolls and the upper and lower backup rolls correspond to the "mill roll".

[0025] Of these rolls, the axial end of the upper work roll 710 is provided on the operating side with a radial bearing 790A (see FIG. 7) that shifts in the axial direction of the roll together with the upper work roll 710 and receives the load from the roll, and this radial bearing 790A is supported by an upper operating-side bearing chock 712A. Similarly, the drive side is provided with a radial bearing 790B (see FIG. 7) that shifts in the axial direction of the roll together with the upper work roll 710 and receives the load from the roll, and this radial bearing 790B is supported by an upper drive-side bearing chock 712B. The operating-side radial bearing 790A and the drive-side radial bearing 790B are configured to support not only the roll bending force acting in the vertical direction but also the thrust force acting in the axial direction of the roll.

[0026] Similarly, the lower work roll 711 is provided with bearings (not shown in the figure) at both the drive and operating sides of its axial ends, and these bearings are supported by lower work roll bearing housings 713 (bearing housing 713A on the operating side, and bearing housing 713B on the drive side).

[0027] In this embodiment, the upper work roll 710 is configured to be shiftable in the roll axis direction by a shift cylinder 715 as shown in Fig. 3 via an upper operating-side bearing housing 712A on the operating side and an upper driving-side bearing housing 712B on the driving side. Similarly, the lower work roll 711 is configured to be shiftable in the roll axis direction by a shift cylinder 717 as shown in Fig. 3 via a bearing housing 713A on the operating side and a bearing housing 713B on the driving side.

[0028] As shown in FIG. 3, the upper work roll 710 and the lower intermediate roll 721 have tapered portions at their operating side ends, and the lower work roll 711 and the upper intermediate roll 720 have tapered portions at their driving side ends. The upper work roll 710 and the lower work roll 711 are vertically point symmetrical, and the upper intermediate roll 720 and the lower intermediate roll 721 are vertically point symmetrical.

[0029] Returning to Figure 2, the entry-side fixing member 702 is fixed to the housing 700 on the entry side of the rolled material 5. An exit-side fixing member 703 is fixed to the housing 700 on the exit side of the rolled material 5 so as to face the entry-side fixing member 702.

[0030] In the fifth stand 70, as shown in FIG. 2, on both the operating side and the drive side, the upper work roll bearing housing 712 is supported by two upper work roll bending cylinders 740, 742 provided in the axial direction of the rolls on the entry-side fixed member 702, and two upper work roll bending cylinders 741, 743 provided in the axial direction of the rolls on the exit-side fixed member 703.

[0031] By appropriately driving these cylinders, a bending force is applied in the vertical direction to the bearing of the upper work roll 710.

[0032] Similarly, on both the operating side and the driving side, the lower work roll bearing housing 713 is supported by lower work roll bending cylinders 744, 746 provided on the entry-side fixed member 702 and lower work roll bending cylinders 745, 747 provided on the exit-side fixed member 703, and by appropriately driving these cylinders, a bending force is applied in the vertical direction to the bearing of the lower work roll 711.

[0033] Of these cylinders, the upper work roll bending cylinders 740, 741 are arranged so as to apply a bending force to the bearing of the upper work roll 710 that contacts the rolled material 5 in the vertical increase direction (toward the opposite side of the rolled material). In addition, the upper work roll bending cylinders 742, 743 are arranged so as to apply a bending force to the bearing in the vertical decrease direction (toward the rolled material), which is the opposite direction to that of the upper work roll bending cylinders 740, 741.

[0034] Similarly, the bottom work roll bending cylinders 744, 745 are arranged to apply a bending force in the vertical increase direction to the bearing of the bottom work roll 711 that contacts the rolled material 5. Furthermore, the bottom work roll bending cylinders 746, 747 are arranged to apply a bending force in the decrease direction to the bearing, which is opposite to the direction of the bottom work roll bending cylinders 744, 745.

[0035] Furthermore, as shown in FIG. 2, for the purpose of removing backlash, two upper work roll bearing housing backlash removing cylinders 760 are provided in the axial direction of the roll on the entry side of the fixed member 702 on the entry side of the rolled material 5 so as to apply a horizontal force, specifically a pressing force in the rolling direction, to the upper work roll 710 via a liner (not shown) of the upper work roll bearing housing 712.

[0036] Similarly, the entry-side fixed member 702 is provided with two lower work roll bearing housing backlash eliminating cylinders 762 so as to apply a pressing force in the rolling direction to the lower work roll 711 via the liner of the lower work roll bearing housing 713.

[0037] These cylinders can apply a desired force to the upper work roll 710 etc. in a direction perpendicular to the roll axis direction.

[0038] Furthermore, as shown in FIG. 2, a hydraulic cylinder 705A may be provided on both the drive side and the operation side of the outlet side of the housing 700 as a horizontal actuator for adjusting the angle of the upper work roll 710 in the horizontal direction.

[0039] Similarly, a hydraulic cylinder 705B may be provided on both the drive side and the operation side of the outlet side of the housing 700 as a horizontal actuator for adjusting the angle of the lower work roll 711 in the horizontal direction.

[0040] Furthermore, hydraulic cylinders 705E and 705F may be provided on both the drive side and operation side of the outlet side of the housing 700, and hydraulic cylinders 706C and 706D may be provided on both the drive side and operation side of the inlet side of the housing 700 as horizontal actuators for adjusting the angles of the upper intermediate roll 720, the lower intermediate roll 721, the upper backup roll 730, and the lower backup roll 731 in the horizontal direction.

[0041] The hydraulic cylinders 705A, 705B, 705E, 705F, 706C, and 706D serving as horizontal actuators are not limited to hydraulic cylinders, and may be configured in other ways, such as with worm gears.

[0042] Bearings (not shown) are provided at both the drive side and the operation side of the upper intermediate roll 720 at the axial end portions, and these bearings are supported by an upper intermediate roll bearing box 722. Similarly, bearings (not shown) are provided at both the drive side and the operation side of the lower intermediate roll 721 at the axial end portions, and these bearings are supported by a lower intermediate roll bearing box 723.

[0043] On both the operating side and the driving side, the upper intermediate roll 720 supports the upper intermediate roll bearing box 722 by an upper intermediate roll bending cylinder 750 provided on the entry side fixed member 702 and an upper intermediate roll bending cylinder 751 provided on the exit side fixed member 703, and by appropriately driving these cylinders, a bending force is applied to the bearing in the vertical increase direction.

[0044] On both the operating side and the driving side of the lower intermediate roll 721, the lower intermediate roll bearing box 723 is supported by a lower intermediate roll bending cylinder 752 provided on the entry side fixed member 702 and a lower intermediate roll bending cylinder 753 provided on the exit side fixed member 703, and by appropriately driving these cylinders, a bending force is applied to the bearing in the vertical increase direction.

[0045] 2, an upper intermediate roll bearing box clearance removing cylinder 771 is provided in the outlet housing 700 so as to apply a horizontal force to the upper intermediate roll 720 via the upper intermediate roll bearing box 722. Similarly, a lower intermediate roll bearing box clearance removing cylinder 773 is provided in the outlet housing 700 so as to apply a horizontal force to the lower intermediate roll 721 via the lower intermediate roll bearing box 723.

[0046] Furthermore, bearings (not shown) are provided at both the drive side and the operation side of the axial end of the upper backup roll 730, and these bearings are supported by an upper backup roll bearing box 732. Similarly, bearings (not shown) are provided at both the drive side and the operation side of the lower backup roll 731, and these bearings are supported by a lower backup roll bearing box 733.

[0047] 2, the entry-side housing 700 is provided with an upper backup roll bearing housing backlash eliminating cylinder 780 so as to apply a horizontal force to the upper backup roll 730 via the upper backup roll bearing housing 732. Similarly, the entry-side housing 700 is provided with a lower backup roll bearing housing backlash eliminating cylinder 782 so as to apply a horizontal force to the lower backup roll 731 via the lower backup roll bearing housing 733.

[0048] The hydraulic device 90 is connected to each hydraulic cylinder, such as the above-mentioned bending cylinders, gap-removing cylinders, shift cylinders 715, 717, hydraulic cylinders 705A, 705B, 705E, 705F, 706C, 706D, and pressure cylinders (not shown) that apply a pressure to the upper work roll 710 and the lower work roll 711 to roll the rolled material 5, and this hydraulic device 90 is connected to the control device 80.

[0049] The control device 80 controls the operation of the hydraulic device 90 to supply and discharge pressure oil to and from the bending cylinders, etc., thereby controlling the drive of each of these cylinders. As a result, the control device 80 is configured to be able to drive, as one example, the drive-side exit shift cylinder 715C (see FIG. 7) and the operation-side exit shift cylinder 715B (see FIG. 7) to shift the upper work roll 710 in the axial direction.

[0050] Next, the characteristic features of the rolling mill and rolling method of the present invention will be described with reference to Figures 4 to 6, taking as an example the configuration relating to the top work roll 710 among the rolls of the fifth stand 70. Note that the same configurations and methods can be used for the bottom work roll 711, top intermediate roll 720, bottom intermediate roll 721, top backup roll 730, and bottom backup roll 731, as well as the work rolls, intermediate rolls, and backup rolls of other stands, and since the detailed configurations are substantially the same, explanations thereof will be omitted.

[0051] First, the problem to be solved by the present invention will be described with reference to Figures 4 to 6. Figures 4 to 6 are schematic diagrams for explaining the problem to be solved by the present invention.

[0052] FIG. 4 shows the moment when the electromagnetic switching valve 810 is excited to b and shifted toward the drive side, and then the electromagnetic switching valve is returned to the neutral position, the pilot check valve is closed, and the shift operation toward the drive side is stopped.

[0053] For ease of explanation, the roll set 710A including the upper work roll 710 is shown in a simplified, integrated form. Shift cylinders are installed on the entry side and the exit side, but because the entry side for the rolled material 5 has substantially the same configuration as the exit side, only the drive-side exit shift cylinder 515C and the operating-side exit shift cylinder 515B on the exit side are shown here.

[0054] As shown in Figure 4, on the drive side, the axial position of roll set 710A is supported by drive side output shift cylinder 515C via drive side arm 714C, and on the drive side, the axial position is supported by operation side output shift cylinder 515B via operation side arm 714B.

[0055] The drive side output shift cylinder 515C is a single rod type cylinder and includes a drive side output plate side hydraulic oil chamber 523a on the rod side, a drive side output opposite plate side hydraulic oil chamber 523b on the head side, a rod 523c, and a piston 523d.

[0056] The operating side output shift cylinder 515B is also a single-rod cylinder and includes an operating side output plate-side hydraulic oil chamber 525a on the rod side, an operating side output anti-plate-side hydraulic oil chamber 525b on the head side, a rod 525c, and a piston 525d.

[0057] In the hydraulic circuit shown in FIG. 4, a pilot check valve 821 and a relief valve 811 are provided on the pressure line 803, and a pilot check valve 822 and a relief valve 812 are provided on the pressure line 804.

[0058] The pressure line 803 branches into a drive side opposite plate side pressure line 505 and an operation side plate side pressure line 506 on the cylinder side of the pilot check valve 821. The drive side opposite plate side pressure line 505 is connected to a drive side outlet side opposite plate side hydraulic oil chamber 523b, and the operation side plate side pressure line 506 is connected to an operation side outlet side plate side hydraulic oil chamber 525a.

[0059] The pressure line 804 branches into a drive side plate-side pressure line 507 and an operating side opposite plate-side pressure line 508 on the cylinder side of the pilot check valve 822. The drive side plate-side pressure line 507 is connected to a drive side outlet plate-side hydraulic oil chamber 523a, and the operating side opposite plate-side pressure line 508 is connected to an operating side outlet opposite plate-side hydraulic oil chamber 525b.

[0060] In the configuration shown in FIG. 4, when the roll set 710A is shifted to the driving side, a thrust resistance force H acting from the roll set 710A to the driving side output shift cylinder 515C and the operation side output shift cylinder 515B is ｔ Is, H ｔ = H ｄ +H ｗ where H ｗ is on the operation side, H ｄ is the force acting on the driving side.

[0061] The operating side outlet side opposite plate side hydraulic oil chamber 525b, which is on the head side of the operating side outlet shift cylinder 515B, and the driving side outlet side plate side hydraulic oil chamber 523a, which is on the rod side of the driving side outlet shift cylinder 515C, are connected by the driving side plate side pressure line 507 and the operating side opposite plate side pressure line 508, so that the pressure p ｄｒ , p ｗｈ are equal.

[0062] However, the cross-sectional area A of the piston 525d that receives pressure on the head side of the operating side output shift cylinder 515B ｗｈ and the cross-sectional area A of the piston 523d ​​that receives pressure on the rod side of the drive-side output shift cylinder 515C. ｄｒ Since there is an area difference between the two, the output Fw of the operating side output shift cylinder 515B is greater than the output Fd of the driving side output shift cylinder 515C, and the thrust resistance acting on the shift cylinder from the roll set 710A is H ｗ >H ｄ The thrust resistance force H acting on the operating arm 714B is ｗ is the larger value.

[0063] In this configuration, let us consider the case where the roll set 710A moves to the drive side by itself. Figure 5 shows the moment when the shift position of the roll set 710A is determined, the pilot check valves 821 and 822 are closed, the shift operation is stopped, and the roll set 710A moves to the drive side by itself and first hits the drive-side arm 714C.

[0064] On the operating side, there is a residual play with respect to the operating-side arm 714B. In actual equipment, the play on the drive side and the play on the operating side will never be exactly the same, so the residual play will never be zero.

[0065] FIG. 6 shows the state where the roll set 710A has further moved toward the driving side from FIG. 5, the remaining backlash on the operating side has become zero, and the movement of the roll set 710A toward the driving side has stopped.

[0066] Here, the area A of the drive-side outlet plate-side hydraulic oil chamber 523a of the drive-side outlet shift cylinder 515C ｄｒ , the area A of the drive side, outlet side, and opposite plate side hydraulic oil chamber 523b ｄｈ, the area A of the operating side outlet plate side hydraulic oil chamber 525a of the operating side outlet shift cylinder 515B ｗｒ , and the area A of the operating side, outlet side, and opposite plate side hydraulic oil chamber 525b ｗｈ But, A ｗｈ =2A ｗｒ And A ｄｈ =2A ｄｒ This shows the case where the relationship is as follows.

[0067] When it first hits the driving side arm 714C, the driving side output shift cylinder 515C is pushed by the thrust resistance force of the roll set 710A. ｄｈ The pressure is rising. ｗｒ Ha p ｄｈ And, A ｗｒ =A ｗｈ / 2, so p ｗｈ = p ｗｒ / 2, also, p ｄｒ = p ｗｈ = p ｗｒ / 2=p ｄｈ / 2.

[0068] Here, A ｄｈ ×p ｄｈ = H ｄ +A ｄｒ ×p ｄｒ Therefore, by substituting the above relationship, A ｄｈ ×p ｄｈ = H ｄ + (A ｄｈ / 2) × (p ｄｈ / 2) relationship is established, and from this equation, H ｄ =A ｄｈ ×p ｄｈ That is, since pressure is also exerted on the rod side of drive-side output shift cylinder 515C, it is only possible to support up to ¾ of the pushing force on the head side of drive-side output shift cylinder 515C.

[0069] Then, the driving side output shift cylinder 515C is H ｄ When the shift cylinder 515C is pushed and loses, the driving side output shift cylinder 515C is pushed and moves by 1.

[0070] Drive side output shift cylinder 515C is H ｄWhen the operating side arm 714B is pushed by the force of the lever 714A and moves in the driving side direction, the operating side arm 714B moves in the operating side so as to reduce the remaining backlash.

[0071] If drive-side output shift cylinder 515C moves by 1 toward the drive side, hydraulic oil flows from drive-side output opposite-plate-side hydraulic oil chamber 523b of drive-side output shift cylinder 515C to operating-side output plate-side hydraulic oil chamber 525a of operating-side output shift cylinder 515B. Therefore, piston 525d of operating-side output shift cylinder 515B wants to move by 2 toward operating-side output opposite-plate-side hydraulic oil chamber 525b, but due to the area difference, operating-side output opposite-plate-side hydraulic oil chamber 525b can only support the pushing force from operating-side output plate-side hydraulic oil chamber 525a with half the pressure of operating-side output plate-side hydraulic oil chamber 525a. Therefore, operating-side output opposite-plate-side hydraulic oil chamber 525b can only move by 1 / 2, which corresponds to the movement of drive-side output plate-side hydraulic oil chamber 523a. Therefore, operating-side output plate-side hydraulic oil chamber 525a cannot move by 2, and only moves by 1 / 2. Therefore, the hydraulic oil equivalent to (2.5) of the hydraulic oil chamber 525 a on the operating side outlet plate side flows out from the relief valve 811 .

[0072] Specifically, if drive-side output shift cylinder 515C moves 1 toward the drive side, operation-side output shift cylinder 515B moves 1 / 2 toward the operation side. This reduces the remaining backlash to 0. Therefore, drive-side arm 714C moves toward the drive side by 2 / 3 of the remaining backlash, and operation-side arm 714B moves toward the operation side by 1 / 3 of the remaining backlash.

[0073] In addition, the driving side output shift cylinder 515C is H ｄ When it is pushed by and moves by 1 in the driving side direction, the rod side of the driving side output shift cylinder 515C also moves by 1, so the head side of the operating side output shift cylinder 515B moves by 1 / 2 in the area ratio, and the rod side of the operating side output shift cylinder 515B also moves by 1 / 2. ｄｈ ×1-A ｗｒ × 1 / 2 = A ｄｈ×3 / 4 of the air is released from relief valve 811. Then, when drive-side arm 714C has moved 2 / 3 of the remaining play and operation-side arm 714B has moved 1 / 3 of the remaining play, drive-side output shift cylinder 515C and operation-side output shift cylinder 515B stop.

[0074] The operating-side arm 714B moves in the operating-side direction by the remaining backlash×⅓, and the position sensor 716 moves by the remaining backlash×⅓.

[0075] The remaining play is the difference between the play on the operating side and the play on the driving side, and if the remaining play is about 1 mm, the position sensor 716 will move about 1 mm×1 / 3=0.3 mm to the operating side.

[0076] As described above, when the roll set 710A is moved toward the drive side while receiving thrust resistance force from the roll set 710A toward the operating side, and the position of the roll set 710A is set, and then, due to a change in conditions such as the rotation of the rolls of the rolling mill, a thrust resistance force toward the drive side acts on the roll set 710A, causing only the roll set 710A to move toward the drive side, the pressure will rise above the set pressure (maximum pressure) of the relief valves 811, 812 before the thrust resistance force is supported by both the drive side and the operating side, and the hydraulic oil will leak out of the relief valves 811, 812.

[0077] In other words, when the drive side alone can support the load, it will do so, but only when the drive side loses will both the drive side and the operating side support the load, and in that case the pressure will exceed the maximum pressure while the hydraulic oil is being released from the relief valves 811 and 812.

[0078] Therefore, there are problems in that the pressure cannot be supported on both sides until it reaches the set pressure of the relief valves 811 and 812, and when the pressure is supported on both sides, it exceeds the set pressure (maximum pressure).

[0079] Furthermore, the shift position of the roll set 710A may shift, so that the shift position must be adjusted frequently.

[0080] The above describes the case where the drive-side arm 714C hits first, leaving the remaining backlash on the operating side, but the same problem occurs when the operating-side arm 714B hits first, leaving the remaining backlash on the drive side.

[0081] Furthermore, the above explanation has shown the problem that occurs when the direction of the thrust resistance force changes, but when the length of roll set 710A changes due to thermal expansion, the same problem occurs because the same condition occurs as when residual play occurs on one side.

[0082] Next, the characteristic configuration of this embodiment that can solve such problems will be described with reference to Figures 7 to 9. Figures 7 to 9 are plan views illustrating the details of the upper work roll portion of the rolling mill.

[0083] As shown in FIG. 7, the operating-side entry-side fixed member 702 is provided with an operating-side entry-side shift cylinder 715A that applies force to the upper work roll 710 in both the operating side and drive side directions via an operating-side arm 714A connected to an upper operating-side bearing housing 712A that supports the operating-side radial bearing 790A.

[0084] In addition, the operating-side exit fixed member 703 is provided with an operating-side exit shift cylinder 715B that applies force to the upper work roll 710 in both the operating side and drive side directions via an operating-side arm 714B connected to an upper operating-side bearing housing 712A that supports the operating-side radial bearing 790A.

[0085] A position sensor 716 is provided at the operating-side outlet shift cylinder 715B to detect the position of the upper work roll 710 in the roll axis direction. The position where the position sensor 716 is provided is not limited to this, and it may be provided at the other operating-side entry shift cylinder 715A or the drive-side shift cylinders 715C and 715D. The number of sensors does not have to be one, and two or more sensors may be provided.

[0086] Similarly, the drive-side entry fixed member 702 is provided with a drive-side entry shift cylinder 715D which applies force to the upper work roll 710 in both the operating side and drive side directions via a drive-side arm 714D connected to an upper drive-side bearing housing 712B which supports the drive-side radial bearing 790B.

[0087] In addition, the drive-side exit fixed member 703 is provided with a drive-side exit shift cylinder 715C that applies force to the upper work roll 710 in both the operating side and drive side directions via a drive-side arm 714C connected to an upper drive-side bearing housing 712B that supports the drive-side radial bearing 790B.

[0088] An axial force acting on the upper work roll 710 also acts on the operating-side radial bearing 790A, and is ultimately supported by operating-side shift cylinders 715A and 715B. Similarly, an axial force acting on the upper work roll 710 acts on the driving-side radial bearing 790B, but this force is supported by driving-side shift cylinders 715C and 715D.

[0089] The axial force acting on the upper work roll 710 is sometimes directed toward the operating side and sometimes directed toward the driving side, so both the operating side shift cylinders 715A, 715B and the driving side shift cylinders 715C, 715D can support forces in either the operating side or driving side direction.

[0090] Each of these operating side entry shift cylinder 715A, operating side exit shift cylinder 715B, driving side exit shift cylinder 715C, and driving side entry shift cylinder 715D is a double-rod type cylinder having two internal pistons 923d, 925d (only the exit side is shown in each case) and two rods 923c, 925c (only the exit side is shown in each case).

[0091] This embodiment also includes a hydraulic circuit configured to supply hydraulic oil to a plurality of hydraulic cylinders, causing the driving side shift cylinders 715C, 715D and the operating side shift cylinders 715A, 715B to move in the axial direction, thereby maintaining the axial position of the upper work roll 710.

[0092] This hydraulic circuit is configured so that after the hydraulic circuit has maintained the axial position of the upper work roll 710, if an external force acting on the upper work roll 710 causes only one of the driving-side shift cylinders 715C, 715D or the operating-side shift cylinders 715A, 715B to apply an axial force to the upper work roll 710, the other of the driving-side shift cylinders 715C, 715D or the operating-side shift cylinders 715A, 715B will move in the opposite direction to the other hydraulic cylinder.

[0093] Also provided are pressure lines 805, 806, 807, and 808 that connect the corresponding hydraulic oil chambers on the inlet and outlet sides. For example, in the hydraulic circuit, the drive side outlet plate-side hydraulic oil chamber 923a, the drive side entry plate-side hydraulic oil chamber 924a, the operating side outlet opposite plate-side hydraulic oil chamber 925b, and the operating side entry opposite plate-side hydraulic oil chamber 926b are connected by a drive side plate-side pressure line 807 and an operating side opposite plate-side pressure line 808, and the drive side outlet opposite plate-side hydraulic oil chamber 923b, the drive side entry opposite plate-side hydraulic oil chamber 924b, the operating side outlet plate-side hydraulic oil chamber 925a, and the operating side entry plate-side hydraulic oil chamber 926a are connected by a drive side opposite plate-side pressure line 805 and an operating side plate-side pressure line 806, so that the drive side shift cylinders 715C, 715D and the operating side shift cylinders 715A, 715B each apply force to the upper work roll 710 in the same direction.

[0094] As a result, when the direction of an external force changes or when the distance between supports on the supported side and the supporting side changes due to thermal expansion of a mechanical device, when either one of the hydraulic cylinders, driving side shift cylinders 715C, 715D or operating side shift cylinders 715A, 715B, moves a predetermined stroke, the hydraulic circuit is configured so that the other hydraulic cylinder, driving side shift cylinders 715C, 715D or operating side shift cylinders 715A, 715B, also moves a predetermined stroke of the same size in the opposite direction without changing the amount of oil in the connected pressure lines 805, 806, 807, 808.

[0095] A radial bearing 790A is disposed in the upper operation-side bearing housing 712A, and a radial bearing 790B is disposed in the upper drive-side bearing housing 712B.

[0096] The radial bearings 790A, 790B are subjected to the forces of the upper work roll bending cylinders 740, 741 and the upper work roll bearing housing backlash eliminating cylinder 760. These radial bearings 790A, 790B support these vertical forces acting on the roll shaft while rotating.

[0097] Furthermore, because the radial bearings 790A, 790B also support the axial force acting on the upper operation-side bearing housing 712A and the upper drive-side bearing housing 712B, four-row tapered roller bearings are generally used. Also, the drive-side radial bearing 790B and the operation-side radial bearing 790A use bearings of the same specifications, which can avoid complicated maintenance work.

[0098] In the drive systems of operating side shift cylinders 715A, 715B and driving side shift cylinders 715C, 715D, electromagnetic switching valves 810 that adjust the amount of oil flowing in and out are provided on the outlet sides of pressure line 801 branching off from pressure line 800A through which pressurized oil discharged from a pump (not shown) of hydraulic device 90 flows, and tank line 802 branching off from tank line 800B connected to a tank (not shown) in which the pressurized oil is stored.

[0099] When the electromagnetic switching valve 810 is excited, the rod side (operating side outlet plate side hydraulic oil chamber 925a side) of the operating side shift cylinders 715A, 715B closer to the plate is connected to pressure lines 801, 800A via the operating side plate side pressure line 806 and pressure line 803, and a force in the operating side direction acts on the upper operating side bearing box 712A.

[0100] In addition, the rod side of the drive side shift cylinders 715C, 715D closer to the opposite plate (the drive side outlet side opposite plate side hydraulic oil chamber 923b side) is also connected to pressure lines 801, 800A via drive side opposite plate side pressure line 805 and pressure line 803, and a force in the operating side direction acts on the upper drive side bearing box 712B.

[0101] Furthermore, the rod side of the operating side shift cylinders 715A, 715B closer to the plate (the operating side outlet side opposite plate side hydraulic oil chamber 925b side) and the rod side of the driving side shift cylinders 715C, 715D closer to the plate (the driving side outlet side plate side hydraulic oil chamber 923a side) are connected to tank lines 802, 800B via operating side opposite plate side pressure line 808 or driving side plate side pressure line 807 and pressure line 804, respectively, so that both the operating side and driving side shift cylinders generate a shift force toward the operating side.

[0102] When the electromagnetic switching valve 810 is energized, the rod side of the operating side shift cylinders 715A, 715B closer to the opposite plate (the operating side outlet side opposite plate side hydraulic oil chamber 925b side) is connected to the pressure lines 801, 800A via the operating side opposite plate side pressure line 808 and pressure line 804, and a force in the drive side direction acts on the upper operating side bearing housing 712A.

[0103] In addition, the rod side of the drive side shift cylinders 715C, 715D closer to the plate (the drive side outlet plate side hydraulic oil chamber 923a side) is connected to pressure lines 801, 800A via drive side plate side pressure line 807 and pressure line 804, and a force in the drive side direction acts on the upper drive side bearing box 712B.

[0104] Furthermore, the rod side closer to the plate of the operating side shift cylinders 715A, 715B (the operating side outlet plate side hydraulic oil chamber 925a side) and the rod side closer to the opposite side to the plate of the driving side shift cylinders 715C, 715D (the driving side outlet opposite plate side hydraulic oil chamber 923b side) are connected to tank lines 802, 800B via the operating side plate side pressure line 806 or the driving side opposite plate side pressure line 805 and pressure line 803, respectively, so that both the operating side and driving side shift cylinders generate a shift force toward the driving side.

[0105] When electromagnetic switching valve 810 is in the neutral position, pilot check valves 821, 822 prevent hydraulic oil from flowing to either the rod side closest to the plate or the rod side opposite to the plate of operating side shift cylinders 715A, 715B and driving side shift cylinders 715C, 715D.

[0106] The configuration of these electromagnetic switching valves 810 and excitation control by the control device 80 allow the operating side shift cylinders 715A, 715B and driving side shift cylinders 715C, 715D to support the upper work roll 710 so that it does not move in the axial direction when the axial shift of the upper work roll 710 is stopped.

[0107] A pilot check valve 822 is provided in pressure line 804 downstream of solenoid directional control valve 810, and a pilot check valve 821 is provided in pressure line 803 downstream of solenoid directional control valve 810, which are configured to prevent pressure oil from flowing to both the rod and head sides of operating side shift cylinders 715A, 715B and drive side shift cylinders 715C, 715D when solenoid directional control valve 810 is in neutral. As a result, even when the shifting of upper work roll 710 is stopped, operating side shift cylinders 715A, 715B and drive side shift cylinders 715C, 715D support upper work roll 710 so that it does not move in the axial direction.

[0108] Furthermore, in consideration of emergencies such as the application of unexpected excessive thrust resistance, relief valves 811, 812 are provided between pilot check valves 821, 822 and operating side shift cylinders 715A, 715B and driving side shift cylinders 715C, 715D to limit the pressure rise in the piping to the allowable pressure of the machine.

[0109] The hydraulic system in FIG. 7 only shows the portion for explaining the present invention, and flow control valves, check valves, etc. may be added as needed.

[0110] Figure 8 shows the structure around the inlet side shift cylinders on the operating side and the drive side. In order to explain the operation, Figure 8 only illustrates the case where the piping on the rod side closest to the plate on the operating side is connected to the piping on the rod side opposite the plate on the drive side, but the same can be said for other piping connections.

[0111] In FIG. 8, the center position of the distance between the support positions on the operating side and the driving side is indicated by line M, and F ｓｄｅ is the force with which the drive-side entry shift cylinder 715D supports the upper drive-side bearing housing 712B, F ｓｗｅis the force with which the operating side entry shift cylinder 715A supports the upper operating side bearing housing 712A, L ａ is the distance between the support positions on the operating side and the driving side, F ｔｒ is the thrust force acting on the upper work roll 710. Here, it is assumed that the thrust force acts in the direction of the operating side.

[0112] In the state shown in FIG. ｓｗｅ and F ｓｄｅ are F ｔｒ / 4, and although not shown, the force F ｓｗｄ and the force F by which the drive-side output shift cylinder 715C supports the upper drive-side bearing housing 712B. ｓｄｄ Also F ｔｒ / 4, and the sum of these four is F ｔｒ Then, the thrust force F ｔｒ Support.

[0113] Figure 9 illustrates a situation in which, in Figure 8, the upper work roll 710 is heated by the rolled material 5 during rolling, the radial bearings 790A, 790B generate heat as they rotate under load, and the distance La between the support positions on the operating side and the drive side is extended by ΔLa due to changes in the ambient temperature, etc.

[0114] As shown in FIG. 9, when the distance La between the support positions on the operating side and the driving side changes by ΔLa, the support position on the driving side moves by ΔLa / 2 toward the opposite side to the plate, hydraulic oil flows from the opposite side to the plate of the driving side shift cylinders 715C, 715D to the plate side of the operating side shift cylinders 715A, 715B, and the support position on the operating side moves by ΔLa / 2 toward the opposite side to the plate.

[0115] That is, in the hydraulic circuit of this embodiment, even if the distance La between the support positions on the operating side and the drive side changes by ΔLa, the amount of oil in the pressure lines 805, 806, 807, 808 on the outlet side of the pilot check valves 821, 822 does not change, so the supporting forces for the upper work roll 710 by the operating side shift cylinders 715A, 715B and the supporting forces for the upper work roll 710 by the drive side shift cylinders 715C, 715D can be maintained at the same level, and the balance of the total supporting forces does not change.

[0116] Therefore, line M, which is the center position of the distance between the support positions on the operating side and the drive side, remains at the center position of the distance between the support positions on the operating side and the drive side even if La changes by ΔLa. In other words, since line M is close to the center position of the rolled material 5, even if there is thermal expansion, only a very small amount of axial slippage occurs between the upper work roll 710 and the rolled material 5, and rolling is not hindered.

[0117] Here, the case where thermal expansion occurs is shown, but in the case where thermal contraction occurs, the supporting force does not change and the position of line M does not change either.

[0118] Next, a modified example of this embodiment will be described with reference to Fig. 10. Fig. 10 is a plan view illustrating the details of the upper work roll portion of a rolling mill that is a modified example of the first embodiment.

[0119] FIG. 10 shows an example of a configuration in which, on the operating side, a shift block 712A1 having upper work roll bending cylinders 740, 741 housed therein is connected to operating side shift cylinders 715A, 715B, and, on the driving side, a shift block 712B1 having upper work roll bending cylinders 740, 741 housed therein is connected to driving side shift cylinders 715C, 715D.

[0120] When such shift blocks 712A1, 712B1 are used, the thrust reaction force can be made the same on the operating side and the driving side, just as in the case of the configuration shown in Figure 7, in which the entry-side fixed member 702 and the exit-side fixed member 703 have bending cylinders 740, 741 built in.

[0121] By adopting the configuration of FIG. 7 and further providing a pressure measuring device on the secondary side of the pilot check valves 821 and 822, it becomes possible to measure the thrust force acting on the roll with high precision.

[0122] Next, the effects of this embodiment will be described.

[0123] According to the rolling mill of the first embodiment of the present invention described above, after the hydraulic circuit has maintained the axial position of the top work roll 710, if an external force acting on the top work roll 710 causes only one of the driving-side shift cylinders 715C, 715D or the operating-side shift cylinders 715A, 715B to apply an axial force to the top work roll 710, the other of the driving-side shift cylinders 715C, 715D or the operating-side shift cylinders 715A, 715B is configured to move in the direction opposite to that of the other hydraulic cylinder.

[0124] When the direction of the axial external force acting on the mill roll changes after the axial position of the mill roll has been maintained, even if the backlash of one of the operating side hydraulic cylinder and the driving side hydraulic cylinder disappears first, when one hydraulic cylinder is pushed and no longer supported and moves, the other hydraulic cylinder moves the same amount in the opposite direction to the one hydraulic cylinder. This operation is continuously repeated until the remaining backlash disappears and the other hydraulic cylinder also begins to support the other hydraulic cylinder, thereby preventing a large axial external force from continuing to act on one hydraulic cylinder until the backlash of the other hydraulic cylinder disappears.

[0125] That is, even if thermal expansion occurs, the direction of thrust resistance force changes, or gaps exist in the axial direction of the roll between the bearing housing and the bearing, inside the bearing, between the bearing and the roll, or between the bearing housing and the shift device, as long as excessive thrust resistance force does not act, the thrust reaction forces of the operating side shift cylinders 715A, 715B and the driving side shift cylinders 715C, 715D themselves can be made the same, and it is possible to prevent the pressure inside the hydraulic cylinders from rising above the set pressure of the relief valves 811, 812. As a result, excessive load is not applied to support parts such as the operating side bearings and driving side bearings of the mill roll, and life can be improved. For example, if the life of a bearing is Lh and the load is Pl, in the case of a roller bearing, Lh ∝ (1 / Pl) １０／３ Since the above relationship exists, if 1 / 2 is added to Pl, Lh = 10, so the life of the bearing can be extended by 10 times compared to when the thrust force is maintained on one side.

[0126] Furthermore, in the conventional configuration, if the pressure rises above the relief valve set pressure, hydraulic oil flows out from the secondary side of the pilot check valve, causing a shift in the shift position and necessitating frequent adjustment of the shift position. However, the configuration of this embodiment can prevent the pressure from rising above the set pressure of the relief valves 811 and 812, eliminating the need for frequent adjustment of the shift position. In other words, the complicated pressure measuring device and adjustment of the inflow / outflow oil amount adjusting section, as in the conventional configuration, are no longer necessary, allowing for a simple device configuration. In addition, since this can be achieved by only controlling the ON / OFF of the solenoid directional control valve 810 without a complex control device, the device configuration of the control system can also be simplified.

[0127] For example, in the case of the above-mentioned Patent Document 1, the thrust force may be supported on one side or on both sides, and the state of thrust force support may change before and after the relief valve is actuated. Furthermore, the operating pressure of the relief valve affects the pressure on the secondary side of the pilot check valve, but because the operating pressure of the relief valve changes depending on the flow rate, it may be difficult to determine from the results of measuring the pressure on the secondary side of the pilot check valve whether the thrust force is supported on one side or both sides. Therefore, even if a pressure measuring device is installed on the secondary side of the pilot check valve and the pressure is measured, the thrust force is calculated by multiplying the areas of both pressure chambers of the cylinder. Therefore, it has been found that it may be difficult to accurately calculate the thrust force if it remains uncertain whether the thrust force is supported on one side or both sides of the cylinder.

[0128] However, in the configuration of this embodiment, the thrust force can always be supported on both sides, even when an abnormal thrust force acts and causes the relief valves 811 and 812 to operate, so the thrust force can be accurately determined from the pressure measurement results on the secondary side of the pilot check valves 821 and 822.

[0129] Furthermore, a rolling mill in which the upper and lower rolls are inclined in opposite directions to each other to form a cross state has a high ability to control the crown and shape of the plate, but since a large thrust force acts between the rolled material 5 and the upper work roll 710, there is a limit to the load capacity depending on the strength of the bearings and roll ends that receive the thrust force.

[0130] In particular, when the load conditions are severe, grease cannot be used to lubricate the bearings and it becomes necessary to use oil lubrication such as circulating oil supply. However, using oil lubrication such as circulating oil supply requires complex equipment and high equipment costs.

[0131] In contrast, if the applied load can be halved by adopting the configuration of the present embodiment, simple grease lubrication can be adopted as mechanical equipment, which has the advantage of keeping equipment costs and operating costs low. Furthermore, if the applied load can be halved, the diameter of the upper work roll 710 can be reduced, which leads to a reduction in the rolling load, making it applicable to rolling hard materials.

[0132] In the above explanation, we have described a case where the bearing receives both bending force and thrust force, but there are also cases where a radial bearing that receives bending force and a thrust bearing that receives thrust force are provided separately. The structure of the bearing is selected appropriately, and even in such a structure, by adopting the configuration of this embodiment, the load acting can be halved, leading to an extension of the life of the roll support parts such as bearings.

[0133] Furthermore, the vertical resistance of the thrust bearing affects the rolling load measurement value. If a thrust force support device is installed on only one side, it can also cause differential load. By adopting the configuration of this embodiment, the thrust force can be made the same on the operating side and the driving side, so differential load can be minimized, although this depends on the friction coefficient of the thrust bearing.

[0134] For this reason, by adopting the configuration of this embodiment, it is possible to achieve a structure that reduces the resistance to movement of the thrust receiving portion in the rolling direction, thereby making it possible to reduce the resistance when changing the inclination during rolling.

[0135] Furthermore, the hydraulic circuit is configured so that the drive side outlet plate-side hydraulic oil chamber 923a and the operating side outlet opposite plate-side hydraulic oil chamber 925b are connected by pressure lines 807, 808, and the drive side outlet opposite plate-side hydraulic oil chamber 923b and the operating side outlet plate-side hydraulic oil chamber 925a are connected by pressure lines 805, 806, so that the drive side shift cylinders 715C, 715D and the operating side shift cylinders 715A, 715B each apply force to the upper work roll 710 in the same direction. This prevents the amount of hydraulic oil moving through the piping from changing.

[0136] Furthermore, the hydraulic circuit is configured so that when either one of the hydraulic cylinders, drive side shift cylinders 715C, 715D or operating side shift cylinders 715A, 715B, moves a predetermined stroke, the other hydraulic cylinder, drive side shift cylinders 715C, 715D or operating side shift cylinders 715A, 715B, also moves a predetermined stroke in the opposite direction without changing the amount of oil in the connected pressure lines 805, 806, 807, 808. This allows the strokes on both the drive side and operating side to be moved to be the same, prevents the pressure in the piping from becoming so high that it exceeds the set pressure of relief valves 811, 812, and allows force to be applied in the same direction to the mill rolls on both the drive side and operating side to support the thrust force.

[0137] Further, the driving side shift cylinders 715C, 715D and the operating side shift cylinders 715A, 715B are double rod cylinders, and the cross-sectional area in the direction in which the force of the hydraulic oil is applied of the driving side outlet plate-side hydraulic oil chamber 923a and the driving side outlet opposite plate-side hydraulic oil chamber 923b is the same, and the cross-sectional area in the direction in which the force of the hydraulic oil is applied of the operating side outlet plate-side hydraulic oil chamber 925a and the operating side outlet opposite plate-side hydraulic oil chamber 925b is the same, and the driving side outlet plate-side hydraulic oil chamber 923a and the operating side outlet opposite plate-side hydraulic oil chamber 925b are connected to the pressure line 8 807, 808, and the drive-side outlet-opposite-plate hydraulic oil chamber 923b and the operating-side outlet-plate-side hydraulic oil chamber 925a are connected by pressure lines 805, 806, so that the force supporting the thrust force in the operating side direction acting on the mill roll and the force supporting the thrust force in the drive side direction can be made equal, and when the operating-side and drive-side bearings of the mill roll have the same specifications, the life of supporting parts such as bearings can be maximized and damage to each part due to load can be reduced. Furthermore, by using a double-rod, the bearing housing connection part for the drive-side hydraulic cylinder and the operating-side hydraulic cylinder can be closer to the plate, so the structure around the bearing housing connection part can be made symmetrical on the drive side and the operating side, making it possible to standardize the structure and resulting in a simpler device than the other embodiments described below.

[0138] Furthermore, the driving side shift cylinders 715C, 715D and the operating side shift cylinders 715A, 715B are each provided on the inlet and outlet sides of the rolling mill, and by providing pressure lines 805, 806, 807, 808 that connect the corresponding hydraulic oil chambers on the inlet and outlet sides, the support force on the inlet and outlet sides of the hydraulic cylinders can be made the same, so that no moment acts on the bearing housing, preventing rotation of the mill roll in the horizontal plane, and also making it possible to equalize the support force on the inlet and outlet sides of the rolled material 5 with a simple structure.

[0139] The mill roll is also provided with a control device 80 that controls the operation of multiple hydraulic cylinders. The control device 80 is configured to drive the drive side shift cylinders 715C, 715D and the operation side shift cylinders 715A, 715B to shift the upper work roll 710 in the axial direction, thereby enabling automatic axial shifting of the mill roll.

[0140] Furthermore, a horizontal actuator is provided to adjust the angle of each roll horizontally. If the mill roll is tilted at an arbitrary angle relative to the plate, the thrust force acting on the mill roll increases, but this large thrust force is supported by half on the operating side and half on the driving side, making the support forces on the entry and exit sides equal with a simple structure, preventing moment from acting on the bearing housing, and reducing the support force per hydraulic cylinder to one-fourth.

[0141] It is also possible to change the diameters of the two rods in a single hydraulic cylinder having two rods, that is, to make the cross-sectional areas of the two hydraulic oil chambers different.

[0142] In this case, the cross-sectional areas of the hydraulic oil chambers on the drive side closer to the plate and the operation side closer to the opposite side to the plate are matched and connected with piping, and the cross-sectional areas of the drive side closer to the opposite side to the plate and the operation side closer to the plate are matched and connected with piping.This allows the opposite side to the plate on the drive side and the operation side closer to the plate, and the drive side closer to the plate and the operation side closer to the opposite side to the plate, to each apply the same thrust reaction force, which makes it possible to halve the thrust reaction force and make it possible to have the same supporting force on the drive side and the operation side, maximizing the life of roll supporting parts such as bearings.

[0143] Furthermore, if it is desired to selectively increase the force supporting the thrust force in the direction of the operating side, it is possible to choose to provide a difference in the rod diameter so that the cross-sectional area of ​​the hydraulic oil chambers on the operating side near the plate and on the drive side near the plate is larger than the cross-sectional area of ​​the hydraulic oil chambers on the operating side near the plate and on the drive side near the plate.

[0144] <Embodiment 2> A rolling mill and a rolling method according to embodiment 2 of the present invention will be described with reference to Fig. 11. Fig. 11 is a plan view illustrating the details of the upper work roll portion of the rolling mill according to embodiment 2.

[0145] In the rolling mill of this embodiment shown in Figure 11, the drive side outlet shift cylinder 715C1, drive side entry shift cylinder 715D1, operation side entry shift cylinder 715A1, and operation side outlet shift cylinder 715B1 are all single-rod cylinders, and the single rods 923c1, 925c1 of each cylinder (only the outlet side is shown in each example) are oriented in the same direction and are arranged on the operation side.

[0146] For this purpose, the operating side entry shift cylinder 715A1 is connected to the operating side arm 714A and the upper operating side bearing housing 712A via a transmission member 715A2, and the operating side exit shift cylinder 715B1 is connected to the operating side arm 714B and the upper operating side bearing housing 712A via a transmission member 715B2, thereby supporting the upper work roll 710.

[0147] Furthermore, the drive side outlet plate side hydraulic oil chamber 923a1 and the operation side outlet opposite plate side hydraulic oil chamber 925b1 are connected by drive side plate side pressure lines 807A, 807B, and the cross-sectional areas in the direction in which the hydraulic oil force is applied (areas of pistons 923d1 and 925d1) are the same, and the drive side outlet opposite plate side hydraulic oil chamber 923b1 and the operation side outlet plate side hydraulic oil chamber 925a1 are connected by pressure lines 805A, 805B and operation side plate side pressure line 806, and the cross-sectional areas in the direction in which the hydraulic oil force is applied (areas of pistons 923d1 and 925d1) are the same.

[0148] With this configuration, as with the configuration of Figure 7 described in Example 1, even if there is thermal deformation of ΔLa, the drive side and the operation side can be moved to opposite sides by ΔLa / 2 on each side of the line M, making it possible to support the drive side and the operation side with equal force.

[0149] That is, after the roll set 710A is moved toward the drive side while receiving a thrust resistance force toward the operating side from the roll set 710A and the position of the roll set 710A is set, a thrust resistance force toward the driving side acts on the roll set 710A due to a change in conditions such as the rotation of the rolls of the rolling mill, and when only the roll set 710A moves toward the driving side, the thrust resistance force can be supported equally on both the drive side and the operating side, so the pressure will not rise above the set pressure of the relief valves 811, 812.

[0150] Even in this case, relief valves 811 and 812 may be provided on the secondary side of the pilot check valves 821 and 822 in consideration of an emergency such as the application of an unexpectedly large thrust resistance force.

[0151] The other configurations and operations are substantially the same as those of the rolling mill and rolling method of the first embodiment, and details thereof will be omitted.

[0152] The rolling mill and rolling method according to the second embodiment of the present invention also provide substantially the same effects as those of the rolling mill and rolling method according to the first embodiment described above.

[0153] In addition, in this embodiment, the same hydraulic cylinder can be used on the operating side and the driving side, but the mechanical devices around the cylinder, such as the shift device, have different structures on the operating side and the driving side. This makes the equipment more complex, but the amount of protrusion of the shift device, including the shift cylinder, from the operating side housing can be made smaller than in the configuration of Example 1, so this configuration can be suitably adopted when it is difficult to make the shift device larger due to the need to accommodate a changeover device on the operating side, etc.

[0154] Specifically, the roll changing device on the operating side can be arranged close to the rolling mill side, and the same can be done as when a shift cylinder is provided only on the operating side of a normal work roll shift, so there is no need to expand the space on the operating side, and space can be saved economically.

[0155] Additionally, if there are space constraints on the drive side due to the device, it is also possible to arrange the head side of the operating side shift cylinders 715A1, 715B1 to be the side opposite the plate, and the head side of the drive side shift cylinders 715C1, 715D1 to be the side closer to the plate.

[0156] The configuration of this embodiment is preferable when securing space on the operation side regardless of whether it is hot rolling or cold rolling.

[0157] 11, the configuration of the single-rod cylinder of this embodiment is not limited to the form shown in Fig. 11, and the drive-side output shift cylinder 715C1 and the drive-side entry shift cylinder 715D1 can also be configured so that the single rod faces outward in the axial direction by supporting the drive-side arms 714C, 714D via a transmission member, similar to the operation-side entry shift cylinder 715A1 and the operation-side output shift cylinder 715B1. In this case, an intermediate cylinder is further provided as shown in Fig. 14, which will be described later.

[0158] Positioning the shift cylinder so that the rods face outward in this way makes the rolling mill more compact. This allows for more space to be secured for roll changeovers on the operating side, and the drive side is similarly compact, allowing for more space to be secured. Furthermore, because the drive side structure can be made symmetrical with the operating side structure, it is possible to standardize the structure and achieve a simpler equipment configuration.

[0159] <Embodiment 3> A rolling mill and a rolling method according to embodiment 3 of the present invention will be described with reference to Figures 12 and 13. Figures 12 and 13 are plan views illustrating the details of the upper work roll portion of the rolling mill according to embodiment 3.

[0160] In the rolling mill of this embodiment shown in Figures 12 and 13, a pressure line 805B1 branching off from the pressure line 803 is connected to the drive side inlet side opposite plate side hydraulic oil chamber 833b of the drive side inlet side shift cylinder 833 of both rods, and a pressure line 805B2 branching off from the pressure line 803 is connected to the operation side inlet side plate side hydraulic oil chamber 830a of the operation side inlet side shift cylinder 830 of both rods.

[0161] Furthermore, the driving side inlet side opposite plate side hydraulic oil chamber 833b and the driving side outlet side opposite plate side hydraulic oil chamber 832b of the driving side outlet side shift cylinder 832 of both rods are connected by a pressure line 823, this driving side outlet side opposite plate side hydraulic oil chamber 832b and the operating side outlet side plate side hydraulic oil chamber 831a of the operating side outlet side shift cylinder 831 of both rods are connected by a pressure line 824, and this operating side outlet side plate side hydraulic oil chamber 831a and the operating side inlet side plate side hydraulic oil chamber 830a are connected by a pressure line 825.

[0162] In order to explain the operation, only the case where the rod side closer to the plate on the operating side and the rod side closer to the opposite side to the plate on the drive side are connected by piping is described, but the rod side closer to the opposite side to the plate on the operating side (operating side inlet opposite side plate hydraulic oil chamber 830b, operating side outlet opposite side plate hydraulic oil chamber 831b) and the rod side closer to the plate on the drive side (drive side inlet plate side hydraulic oil chamber 833a, drive side outlet plate side hydraulic oil chamber 832a) are also connected by piping in the same way.

[0163] 12 and 13, it is assumed that a thrust force in the operating side direction is acting, as in FIG.

[0164] 13 shows a state in which the upper work roll 710 in FIG. 12 has an arbitrary inclination angle with respect to the rolled material 5. The center of the width of the plate at the plate passing position is set to be approximately the same position as the center of the rolling mill, and in this case, the inclination angle θ is set with the center position of the rolling mill in the plate width direction as the center. ｃ are arranged counterclockwise.

[0165] In FIG. 13, the inclination angle θ ｃ When the distance from the rolling mill center position to the thrust force acting position is the same on the operating side and the driving side, the support position on the inlet side of the operating side is ΔL ｗｅ The support position on the operation side is ΔL ｗｄ Furthermore, the support position on the drive side moves toward the opposite side of the plate by ΔL ｄｅ The support position on the drive side is ΔL ｄｄ Move closer to the board.

[0166] These movements cause hydraulic oil to move within pressure lines 805B1, 805B2, 823, 824, and 825, but the total amount of hydraulic oil on the outlet side (secondary side) of pilot check valves 821 and 822 does not change.

[0167] Since the rod side opposite the plate on the operating side and the rod side closer to the plate on the drive side are similarly connected by pressure lines, the total amount of hydraulic oil on the outlet side (secondary side) of the pilot check valves 821, 822 does not change.

[0168] On the other hand, the upper work roll 710 can shift to various positions, and even when it does not shift, the distance from the rolling mill center to the thrust force acting position may differ between the operating side and the driving side.

[0169] In this case, the distance between the support positions on the operating side and the drive side changes slightly as the upper work roll 710 tilts. This change causes a flow of hydraulic oil between the operating side and the drive side, just as occurs when the distance between the support positions on the operating side and the drive side changes due to thermal expansion of the upper work roll 710 or the like. However, ΔL ｗｅ , ΔL ｗｄ , ΔL ｄｅ , ΔL ｄｄ Although the values ​​of (a) and (b) deviate slightly from the geometrically determined thrust force acting position as the upper work roll 710 inclines, there is no significant change.

[0170] In this way, in a mill that shifts work rolls, when tilting the top work roll 710 during rolling, it is possible to tilt the roll without significantly changing the shift position and without applying an excessive load that would cause the pressure of the relief valves 811, 812 to rise above the set pressure during the tilting process.

[0171] Furthermore, since tilting involves only a slight deviation centered on the line M, the upper work roll 710 can be tilted with almost no slippage between the rolled material 5 and the upper work roll 710.

[0172] After the shift position of the upper work roll 710 has been determined, or even in a mill without a shift, after the axial position of the upper work roll 710 has been determined using the configuration of this embodiment, no undue force will be applied to the shift device even if the inclination angle is changed during rolling or even if the pilot check valves 821, 822 remain in an activated state.

[0173] The deviation in the roll axis direction that accompanies a change in the tilt angle is very small because the deviation between the center of the support position distance and the center of the tilt (rolling mill center position) is small. When this very small deviation occurs, the total amount of hydraulic oil on the secondary side of the pilot check valves 821, 822 does not change.

[0174] In addition, even in other embodiments such as that shown in Figure 11, if the total amount of hydraulic oil on the secondary side of the pilot check valves 821, 822 does not change even if the rolls tilt with respect to the rolled material 5 during rolling, the support forces on the operating side and driving side of each cylinder can be made equal.

[0175] The other configurations and operations are substantially the same as those of the rolling mill and rolling method of the first embodiment, and details thereof will be omitted.

[0176] The rolling mill and rolling method according to the third embodiment of the present invention also provide substantially the same effects as those of the rolling mill and rolling method according to the first embodiment described above.

[0177] <Embodiment 4> A rolling mill and rolling method according to embodiment 4 of the present invention will be described with reference to Fig. 14. Fig. 14 is a plan view illustrating the details of the upper work roll portion of the rolling mill according to embodiment 4. Note that while Fig. 14 only shows the delivery side, the entry side has a similar structure, and details are omitted.

[0178] 14, the driving-side output shift cylinder 935C and the operating-side output shift cylinder 935B are single-rod cylinders. The rod 943c of the driving-side output shift cylinder 935C and the rod 945c of the operating-side output shift cylinder 935B face in opposite directions and are positioned on the rolled material 5 side.

[0179] Furthermore, two single-rod intermediate cylinders are provided: a first intermediate cylinder 971 and a second intermediate cylinder 973. These first intermediate cylinder 971 and second intermediate cylinder 973 are dummy cylinders, and there is no particular object to be pressed.

[0180] In addition, the drive side outlet rod side hydraulic oil chamber 943a of the drive side outlet shift cylinder 935C and the rod side hydraulic oil chamber 971b of the first intermediate cylinder 971 are connected by an intermediate rod pressure line 807C2, and the drive side outlet head side hydraulic oil chamber 943b and the head side hydraulic oil chamber 973a of the second intermediate cylinder 973 are connected by an intermediate rod pressure line 805C2.

[0181] Furthermore, the operating side outlet rod side hydraulic oil chamber 945a of the operating side outlet shift cylinder 935B and the rod side hydraulic oil chamber 973b of the second intermediate cylinder 973 are connected by an intermediate rod pressure line 805C1, and the operating side outlet head side hydraulic oil chamber 945b and the head side hydraulic oil chamber 971a of the first intermediate cylinder 971 are connected by an intermediate rod pressure line 807C1.

[0182] In addition, the ratio of the cross-sectional areas in the direction in which the force of the hydraulic oil is applied between the drive side outlet rod side hydraulic oil chamber 943a and the drive side outlet head side hydraulic oil chamber 943b, the ratio of the cross-sectional areas in the direction in which the force of the hydraulic oil is applied between the operation side outlet rod side hydraulic oil chamber 945a and the operation side outlet head side hydraulic oil chamber 945b, the ratio of the cross-sectional areas in the direction in which the force of the hydraulic oil is applied between the rod side hydraulic oil chamber 971b and the head side hydraulic oil chamber 971a, and the ratio of the cross-sectional areas in the direction in which the force of the hydraulic oil is applied between the rod side hydraulic oil chamber 973b and the head side hydraulic oil chamber 973a are the same for all cylinders.

[0183] In this case, too, when the drive-side arm 714C moves to the drive side by half the remaining backlash, the operation-side arm 714B moves to the operation side by half the remaining backlash, and the amount of hydraulic oil on the secondary side of the pilot check valves 821 and 822 does not change.

[0184] In addition, the cross-sectional area of ​​the operating side shift cylinder 935B and the driving side shift cylinder 935C that the hydraulic oil comes into contact with is A ｗｒ <A ｄｈ , pressure is p ｗｒ >p ｄｈ Then, A ｗｒ ×pｗｒ =Ad ｈ ×p ｄｈ Therefore, the supporting force of the driving side arm 714C and the operating side arm 714B is the same.

[0185] Similarly, when a thrust force acts on the roll set 710A in the direction of the operating side, a thrust reaction force of the same force is generated on the rod side of the driving side and the head side of the operating side, so that even in the configuration of this embodiment, the support force for the thrust force on the operating side and the driving side can be halved.

[0186] The other configurations and operations are substantially the same as those of the rolling mill and rolling method of the first embodiment, and details thereof will be omitted.

[0187] The rolling mill and rolling method of the fourth embodiment of the present invention also provide substantially the same effects as those of the rolling mill and rolling method of the first embodiment described above.

[0188] Furthermore, in the configuration of this embodiment 4, the bearing housing connection portion of the driving side hydraulic cylinder and the bearing housing connection portion of the operating side hydraulic cylinder can be located closer to the rolled material 5, so the structure around the bearing housing connection portion can be made symmetrical on the driving side and the operating side, making it possible to standardize the structure and resulting in a simple device.

[0189] Furthermore, since the length of the hydraulic cylinder is shorter than in the double-rod configuration of Example 1, the protrusion on the operating side of the shift device can be reduced, making it possible to secure space for the roll changing device.

[0190] The piston 973d of the second intermediate cylinder 973, the piston 943d of the driving side output shift cylinder 935C, the piston 945d of the operating side output shift cylinder 935B, and the piston 971d of the first intermediate cylinder 971 can have the same cross-sectional area, but they do not have to be the same; it is sufficient if the ratio of the cross-sectional area of ​​the head / rod side of the piston of each cylinder is the same.

[0191] <Others> The present invention is not limited to the above-described examples, and includes various modifications. The above-described examples have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those having all of the described configurations.

[0192] It is also possible to replace part of the configuration of one embodiment with the configuration of another embodiment, or to add the configuration of one embodiment to the configuration of another embodiment.It is also possible to add, delete, or replace part of the configuration of each embodiment with the configuration of another embodiment.

[0193] For example, the description has been given using a rolling mill in which the mill rolls shift in the roll axial direction as an example, but the present invention also covers a rolling mill that is equipped with a hydraulic cylinder that fixes the axial position, i.e., a rolling mill that does not shift in the axial direction.

[0194] DESCRIPTION OF SYMBOLS 1...Rolling equipment 5...Rolled material 30...First stand (rolling mill) 40...Second stand (rolling mill) 50...Third stand (rolling mill) 60...Fourth stand (rolling mill) 70...Fifth stand (rolling mill) 80...Control device 90...Hydraulic device 700...Housing 702...Entry side fixed member 703...Exit side fixed member 705A, 705B, 705E, 705F, 706C, 706D...Hydraulic cylinder (horizontal actuator) 710...Upper work roll (mill roll) 710A...Roll set 711...Lower work roll (mill roll) 712...Upper work roll bearing housing 712A...Upper operation side bearing housing 712A1...Shift block 712B...Upper drive side bearing housing 712B1...Shift block 713...Lower work roll bearing housing 713A, 713B... Bearing housing 714A, 714B... Operation side arm 714C, 714D... Drive side arm 715... Shift cylinder (hydraulic cylinder) 715A, 715A1, 830... Operation side entry shift cylinder (hydraulic cylinder, operation side hydraulic cylinder) 715A2, 715B2... Transmission member 715B, 715B1, 831, 935B... Operation side exit shift cylinder (hydraulic cylinder, operation side hydraulic cylinder) 715C, 715C1, 832, 935C... Drive side exit shift cylinder (hydraulic cylinder, drive side hydraulic cylinder) 715D, 715D1, 833... Drive side entry shift cylinder (hydraulic cylinder, drive side hydraulic cylinder) 716... Position sensor 717... Shift cylinder (hydraulic cylinder) 720... Upper intermediate roll (mill roll) 721... Lower intermediate roll (mill roll) 722...Upper intermediate roll bearing housing 723...Lower intermediate roll bearing housing 730...Upper backup roll (mill roll) 731...Lower backup roll (mill roll) 732...Upper backup roll bearing housing 733...Lower backup roll bearing housing 740, 741, 742, 743...Upper work roll bending cylinders 744, 745, 746, 747...Lower work roll bending cylinders 750, 751...Upper intermediate roll bending cylinders 752,753...Lower intermediate roll bending cylinder 760...Upper work roll bearing housing play removing cylinder 762...Lower work roll bearing housing play removing cylinder 771...Upper intermediate roll bearing housing play removing cylinder 773...Lower intermediate roll bearing housing play removing cylinder 780...Upper backup roll bearing housing play removing cylinder 782...Lower backup roll bearing housing play removing cylinder 790A, 790B...Radial bearings 800A, 801...Pressure line 800B, 802...Tank line 803, 804...Pressure line 805...Drive side opposite plate side pressure line (piping) 805A, 805B, 805B1, 805B2, 823, 824, 825...Pressure line (piping) 805C1, 805C2...Intermediate rod pressure line (piping) 806...Operation side plate side pressure line (piping) 807...Drive side plate side pressure line (piping) 807A, 807B...Drive side plate side pressure line 807C1, 807C2...Intermediate rod pressure line 808...Operation side opposite plate side pressure line (piping) 810...Electromagnetic directional control valve 811, 812...Relief valve 821, 822...Pilot check valve 830a...Operation side inlet side plate side hydraulic oil chamber 830b...Operation side inlet side opposite plate side hydraulic oil chamber 831a...Operation side outlet side plate side hydraulic oil chamber 831b...Operation side outlet side opposite plate side hydraulic oil chamber 833a...Drive side inlet side plate side hydraulic oil chamber 833b...Drive side inlet side opposite plate side hydraulic oil chamber 832a, 923a, 923a1...Drive side outlet side plate side hydraulic oil chamber (drive side plate side hydraulic oil chamber) 832b, 923b, 923b1... Drive side outlet side opposite plate side hydraulic oil chamber (drive side opposite plate side hydraulic oil chamber) 923c, 925c... Rod 923c1... Single rod (drive side hydraulic cylinder rod) 923d, 923d1, 925d, 925d1, 943d, 945d, 971d, 973d... Piston 924a... Drive side entry side plate side hydraulic oil chamber (drive side plate side hydraulic oil chamber) 924b... Drive side entry side opposite plate side hydraulic oil chamber (drive side opposite plate side hydraulic oil chamber) 925a, 925a1... Operation side exit side plate side hydraulic oil chamber (operation side plate side hydraulic oil chamber) 925b,925b1...Operation side outlet side opposite plate side hydraulic oil chamber (operation side opposite plate side hydraulic oil chamber) 925c1...Single rod (operation side hydraulic cylinder rod) 926a...Operation side entry side plate side hydraulic oil chamber (operation side plate side hydraulic oil chamber) 926b...Operation side entry side opposite plate side hydraulic oil chamber (operation side opposite plate side hydraulic oil chamber) 943a...Drive side outlet side rod side hydraulic oil chamber (drive side plate side hydraulic oil chamber) 943b...Drive side outlet side head side hydraulic oil chamber (drive side opposite plate side hydraulic oil chamber) 943c...Rod (drive side hydraulic cylinder rod) 945a...Operation side outlet side rod side hydraulic oil chamber (operation side plate side hydraulic oil chamber) 945b...Operation side outlet side head side hydraulic oil chamber (operation side opposite plate side hydraulic oil chamber) 945c...Rod (operation side hydraulic cylinder rod) 971...First intermediate cylinder 971a...Head side hydraulic oil chamber 971b... rod side hydraulic oil chamber 973... second intermediate cylinder 973a... head side hydraulic oil chamber 973b... rod side hydraulic oil chamber,

Claims

1. A rolling mill comprising: a mill roll; a plurality of hydraulic cylinders including a drive-side hydraulic cylinder provided on the drive side of the mill roll configured to apply an axial force to the mill roll, and an operating-side hydraulic cylinder provided on the operating side of the mill roll configured to apply the axial force; and a hydraulic circuit configured to supply hydraulic oil to the plurality of hydraulic cylinders, causing the drive-side hydraulic cylinder and the operating-side hydraulic cylinder to move in the axial direction and maintaining the axial position of the mill roll, wherein the hydraulic circuit is configured such that after the hydraulic circuit has maintained the axial position of the mill roll, if an external force received by the mill roll causes only one of the drive-side hydraulic cylinder or the operating-side hydraulic cylinder to apply the axial force to the mill roll, the other of the drive-side hydraulic cylinder or the operating-side hydraulic cylinder will move in the direction opposite to that of the one hydraulic cylinder.

2. A rolling mill as claimed in claim 1, wherein the hydraulic circuit is such that the drive side plate side hydraulic oil chamber and the operating side opposite plate side hydraulic oil chamber are connected by piping, and the drive side opposite plate side hydraulic oil chamber and the operating side plate side hydraulic oil chamber are connected by piping, so that the drive side hydraulic cylinder and the operating side hydraulic cylinder each apply force to the mill roll in the same direction.

3. A rolling mill as claimed in claim 2, wherein the hydraulic circuit is configured so that when either the drive-side hydraulic cylinder or the operating-side hydraulic cylinder moves a predetermined stroke, the other of the drive-side hydraulic cylinder or the operating-side hydraulic cylinder also moves a predetermined stroke in the opposite direction without changing the amount of oil in the connected piping.

4. A rolling mill as claimed in claim 1, wherein the drive side hydraulic cylinder and the operating side hydraulic cylinder are double rod cylinders, the cross-sectional area of ​​the drive side plate side hydraulic oil chamber in the direction in which the force of the hydraulic oil is applied is the same as that of the drive side opposite plate side hydraulic oil chamber, the cross-sectional area of ​​the operating side plate side hydraulic oil chamber in the direction in which the force of the hydraulic oil is applied is the same as that of the operating side opposite plate side hydraulic oil chamber, and the drive side plate side hydraulic oil chamber and the operating side opposite plate side hydraulic oil chamber are connected by piping, and the drive side opposite plate side hydraulic oil chamber and the operating side plate side hydraulic oil chamber are connected by piping.

5. A rolling mill as claimed in claim 1, wherein the drive side hydraulic cylinder and the operating side hydraulic cylinder are single rod cylinders, the drive side hydraulic cylinder rod and the operating side hydraulic cylinder rod are oriented in the same direction, the drive side plate side hydraulic oil chamber and the operating side opposite plate side hydraulic oil chamber are connected by piping and have the same cross-sectional area in the direction in which the force of the hydraulic oil is applied, and the drive side opposite plate side hydraulic oil chamber and the operating side plate side hydraulic oil chamber are connected by piping and have the same cross-sectional area in the direction in which the force of the hydraulic oil is applied.

6. A rolling mill according to claim 1, wherein the drive-side hydraulic cylinder and the operating-side hydraulic cylinder are single-rod cylinders, the drive-side hydraulic cylinder rod and the operating-side hydraulic cylinder rod are oriented in opposite directions, two or more single-rod intermediate cylinders are provided, the drive-side rod-side hydraulic oil chamber and the first intermediate cylinder rod-side hydraulic oil chamber are connected by piping, the drive-side head-side hydraulic oil chamber and the second intermediate cylinder head-side hydraulic oil chamber are connected by piping, the operating-side rod-side hydraulic oil chamber and the second intermediate cylinder rod-side hydraulic oil chamber are connected by piping, and the operating-side head-side hydraulic oil chamber and the first intermediate cylinder head-side hydraulic oil chamber are connected by piping, a rolling mill in which the ratio of the cross-sectional areas of the driving-side rod-side hydraulic oil chamber and the driving-side head-side hydraulic oil chamber in the direction in which the force of the hydraulic oil is applied, the ratio of the cross-sectional areas of the operating-side rod-side hydraulic oil chamber and the operating-side head-side hydraulic oil chamber in the direction in which the force of the hydraulic oil is applied, the ratio of the cross-sectional areas of the first intermediate cylinder rod-side hydraulic oil chamber and the first intermediate cylinder head-side hydraulic oil chamber in the direction in which the force of the hydraulic oil is applied, and the ratio of the cross-sectional areas of the second intermediate cylinder rod-side hydraulic oil chamber and the second intermediate cylinder head-side hydraulic oil chamber in the direction in which the force of the hydraulic oil is applied are the same.

7. A rolling mill according to claim 6, wherein the drive-side hydraulic cylinder rod and the operation-side hydraulic cylinder rod are configured to face outward in the axial direction.

8. A rolling mill according to any one of claims 1 to 7, wherein the driving hydraulic cylinder and the operating hydraulic cylinder are provided on the entry side and exit side of the rolling mill, respectively, and the rolling mill is provided with piping connecting the corresponding hydraulic oil chambers on the entry side and the exit side.

9. A rolling mill according to any one of claims 1 to 7, further comprising a control device for controlling the drive of the plurality of hydraulic cylinders, wherein the control device is configured to drive the drive-side hydraulic cylinder and the operation-side hydraulic cylinder to shift the mill roll in the axial direction.

10. A rolling mill according to any one of claims 1 to 7, comprising a horizontal actuator for adjusting the angle of the mill roll in the horizontal direction.

11. A method for rolling a rolled material using a rolling mill comprising: a mill roll; a plurality of hydraulic cylinders including a drive-side hydraulic cylinder provided on the drive side of the mill roll configured to apply an axial force to the mill roll, and an operation-side hydraulic cylinder provided on the operation side of the mill roll configured to apply the axial force; and a hydraulic circuit configured to supply hydraulic oil to the plurality of hydraulic cylinders, causing the drive-side hydraulic cylinder and the operation-side hydraulic cylinder to move in the axial direction and maintaining the axial position of the mill roll, wherein the hydraulic circuit is configured so that after the hydraulic circuit has maintained the axial position of the mill roll, when an external force received by the mill roll causes only one of the drive-side hydraulic cylinder or the operation-side hydraulic cylinder to apply the axial force to the mill roll, the other of the drive-side hydraulic cylinder or the operation-side hydraulic cylinder moves in the direction opposite to that of the other hydraulic cylinder, and the rolling method for rolling the rolled material.

12. A rolling method as claimed in claim 11, wherein the hydraulic circuit is configured so that the driving side plate-side hydraulic oil chamber and the operating side opposite plate-side hydraulic oil chamber are connected by piping, and the driving side opposite plate-side hydraulic oil chamber and the operating side plate-side hydraulic oil chamber are connected by piping, so that the driving side hydraulic cylinder and the operating side hydraulic cylinder each apply force to the mill roll in the same direction, and the rolling method rolls the rolled material.

13. A rolling method as claimed in claim 12, wherein the hydraulic circuit is configured so that when either the driving side hydraulic cylinder or the operating side hydraulic cylinder moves a predetermined stroke, the other of the driving side hydraulic cylinder or the operating side hydraulic cylinder also moves the predetermined stroke in the opposite direction without changing the amount of oil in the connected piping, thereby rolling the rolled material.

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