A secondary threading method for a reciprocating rolling mill

Abstract

The application discloses a secondary plate threading method of a reciprocating rolling mill, and the secondary plate threading at least comprises the following steps: S10, lifting a clamping roller of an inlet tension reel and pressing an outer circle plate surface of an advanced cut plate steel coil; simultaneously, opening a roll gap of a working roller; S20, clamping a plate head of the advanced cut plate steel coil, and simultaneously, starting the inlet tension reel to make the advanced cut plate steel coil transmit to a direction of an outlet tension reel; S30, when the plate head reaches the roll gap of the working roller, pressurizing a tension force to make the working roller clamp the plate head; S40, simultaneously, rotating the working roller and the inlet tension reel, lifting an outlet guide plate to make the plate head reach the outlet tension reel; S50, clamping the plate head through the outlet tension reel, lowering the outlet guide plate to perform coiling, and completing the secondary plate threading operation; the application is safe and reliable, simple to operate, and does not affect the production cost, product quality and delivery period of the steel plate.

Description

Technical Field

[0001] This invention relates to the field of steel plate manufacturing, specifically to a secondary plate-passing method for a rolling mill, and particularly to a secondary plate-passing method for a reciprocating rolling mill. Background Technology

[0002] In the steel plate manufacturing process, hot-rolled pickled steel coils typically require multiple passes on a reciprocating rolling mill (usually a six-roll reciprocating mill) to meet the steel plate's process requirements. However, in actual steel plate production, due to various unforeseen circumstances such as quality issues and equipment malfunctions, the target thickness may not be achieved during the reciprocating rolling process, necessitating premature cutting. Since the cut coils do not meet the scheduled passes and thus do not fulfill the process requirements, order delivery is impossible.

[0003] Because the inner diameter of the steel coil cut midway through the reciprocating rolling mill (typically 508mm) differs from the diameter of the tension reel of its uncoiler (typically 610mm), this midway-cut coil cannot be directly threaded from the tension reel using the conventional process. Instead, it needs to be sent to a rewinding line to be re-coiled until its diameter matches that of the tension reel before it can be threaded from the tension reel again. This obviously increases the production cost of the steel plate, affects the delivery time, and also carries the risk of affecting the surface quality of the steel plate.

[0004] Therefore, the applicant urgently needs to find technical solutions to address the above technical problems. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a secondary piercing method for a reciprocating rolling mill that is safe, reliable, and easy to operate, while not affecting the production cost, product quality, and delivery time of the steel plate.

[0006] The technical solution adopted in this invention is as follows:

[0007] A method for secondary piercing of a reciprocating rolling mill includes a first piercing and a second piercing. After the first piercing is completed, the steel coil is pre-cut without achieving the predetermined number of passes, resulting in a pre-cut steel coil located on the inlet tension roll. The pre-cut steel coil is then pierced a second time.

[0008] The second insertion of the plate includes at least the following steps:

[0009] S10) Lift the pressing roller of the inlet tension roll to press down on the outer ring of the pre-cut steel coil; at the same time, open the roller gap of the work roll;

[0010] S20) Clamp the head of the pre-cut steel coil and simultaneously jog the inlet tension reel, so that the pre-cut steel coil is conveyed toward the outlet tension reel.

[0011] S30) When the plate head reaches the roll gap of the work roll, a pressing force is applied to make the work roll clamp the plate head;

[0012] S40) Simultaneously rotate the working roller and the inlet tension roller to lift the outlet guide plate so that the plate head reaches the outlet tension roller.

[0013] S50) The plate head is clamped by the exit tension roller, and the exit guide plate is lowered for winding to complete the second plate threading operation.

[0014] Preferably, the first threading process involves feeding the steel coil from the tension reel of the uncoiler, threading it through the outlet tension reel of the reciprocating mill to the inlet tension reel of the reciprocating mill.

[0015] Preferably, the first spooling involves feeding the steel coil from the tension reel of the uncoiler, spooling it from the tension reel of the uncoiler to the exit tension reel of the reciprocating mill for uncoiling pass rolling, and then spooling the steel coil that has been rolled from the uncoiling pass from the exit tension reel to the entrance tension reel of the reciprocating mill for reciprocating rolling.

[0016] Preferably, in step S10), before lifting the pressure roller of the inlet tension roll, the pins of the X-ray protection cover, scissors, pressure plate and feed roller of the reciprocating rolling mill are respectively inserted to prevent mechanical injury to personnel caused by misoperation.

[0017] Preferably, in step S20), pliers are used to clamp the head of the pre-cut steel coil.

[0018] Preferably, in step S30), the pressure is increased to 70-100 tons to ensure that the work roll clamps the plate head.

[0019] Preferably, the reciprocating mill is a six-roll reciprocating mill.

[0020] Preferably, the diameter of the inlet tension reel is smaller than the diameter of the uncoiler tension reel.

[0021] Preferably, the diameter of the inlet tension reel is 495-515 mm.

[0022] Preferably, the diameter of the tension roll of the uncoiler is greater than 600 mm.

[0023] Considering that due to unforeseen circumstances, steel coils may need to be pre-cut during the steel plate rolling process if the predetermined rolling passes are not met, this application proposes a method for performing a second rolling operation on pre-cut steel coils to avoid the existing method of rewinding the steel coils before threading them. This method mainly involves clamping the head of the steel coil while simultaneously jogging the inlet tension roller to slowly feed the coil forward, preventing the head from inserting into the gaps in the equipment. When the head reaches the gap between the work rolls, the work rolls apply pressure to clamp the head. Then, by simultaneously rotating the work rolls and the inlet tension roller, and raising the outlet guide plate, the head is fed to the outlet tension roller. Finally, the outlet tension roller clamps the head, and the outlet guide plate is lowered for winding, completing the second rolling operation. This is equivalent to performing the rolling operation in reverse from the outlet. The proposed solution is safe, reliable, and simple to operate, and does not affect the production cost, product quality, or delivery time of the steel plates. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structural state of a six-roll reciprocating rolling mill performing the second plate-passing in a specific embodiment of the present invention;

[0025] Figure 2 This is a flowchart of the operation steps for the second insertion of the plate under a specific embodiment of the present invention. Detailed Implementation

[0026] This invention discloses a secondary threading method for a reciprocating rolling mill, comprising a first threading and a second threading. After the first threading is completed, the steel coil is pre-cut without achieving the predetermined number of passes, resulting in a pre-cut steel coil located on the inlet tension roll. The pre-cut steel coil is then threaded a second time. The second threading includes at least the following steps: S10) Lifting the clamping roller of the inlet tension roll to press down on the outer surface of the pre-cut steel coil; simultaneously opening the roll gap of the work roll; S20) Clamping the head of the pre-cut steel coil, while simultaneously jogging the inlet tension roll to convey the pre-cut steel coil towards the outlet tension roll; S30) When the head reaches the roll gap of the work roll, applying a rolling force to clamp the head of the work roll; S40) Simultaneously rotating the work roll and the inlet tension roll, lifting the outlet guide plate to bring the head of the coil to the outlet tension roll; S50) Clamping the head of the coil with the outlet tension roll, lowering the outlet guide plate for winding, thus completing the second threading operation.

[0027] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0028] Please see Figure 1 and Figure 2 As shown, a secondary piercing method for a reciprocating rolling mill includes a first piercing and a second piercing. Preferably, in this embodiment, the reciprocating rolling mill is a six-roll reciprocating rolling mill, and the diameter of the inlet tension roll is smaller than the diameter of the uncoiler tension roll. The diameter of the inlet tension roll is 495-515mm, and the diameter of the uncoiler tension roll is greater than 600mm. More preferably, in this embodiment, the diameter of the inlet tension roll is 508mm, and the diameter of the uncoiler tension roll is 610mm.

[0029] Preferably, in this embodiment, the first threading operation adopts a known threading process, in which the steel coil is fed from the tension coil of the uncoiler, and then threaded through the tension coil at the exit of the reciprocating mill to the tension coil at the entrance of the reciprocating mill; more specifically, in this embodiment, the first threading operation adopts the method of feeding the steel coil from the tension coil of the uncoiler, threading through the tension coil from the tension coil to the exit tension coil of the reciprocating mill for uncoiling pass rolling, and then threading the steel coil that has been rolled from the uncoiling pass through the exit tension coil to the entrance tension coil of the reciprocating mill for reciprocating rolling;

[0030] After the first slab threading was completed, due to an unexpected situation, the steel coil was cut ahead of schedule without achieving the predetermined number of passes, resulting in the pre-cut steel coil 1 located on the inlet tension coil. The pre-cut steel coil 1 was then threaded a second time.

[0031] In this embodiment, the second insertion of the plate includes at least the following steps:

[0032] S10) Lift the clamping roller 11a of the inlet tension roll 10a to press down on the outer ring of the pre-cut steel coil 1 to prevent the pre-cut steel coil 1 from loosening; at the same time, open the roll gap of the work roll 12; preferably, in this S10) step, before lifting the clamping roller 11a of the inlet tension roll 10a, insert the pins of the X-ray protection cover 13b, scissors 13c, pressure plate 13d and feed roller 13a of the reciprocating rolling mill to prevent mechanical injury to personnel caused by misoperation;

[0033] S20) Clamp the head of the pre-cut steel coil 1 and simultaneously jog the inlet tension reel 10a to slowly convey the pre-cut steel coil 1 towards the outlet tension reel 10b, preventing the head of the pre-cut steel coil 1 from inserting into the equipment gap; preferably, in this step S20), a plier is used to clamp the head of the pre-cut steel coil 1. After the head passes the plate roll of the reciprocating rolling mill, the plier is no longer needed, and it can continue to be conveyed forward by jogging the inlet tension reel 10a;

[0034] S30) When the plate head reaches the roll gap of the work roll 12, apply a rolling force (preferably 70-100 tons) to ensure that the work roll 12 clamps the plate head;

[0035] S40) Simultaneously rotate the working roller 12 and the inlet tension roller 10a, and lift the outlet guide plate 11b so that the plate head reaches the outlet tension roller 10b;

[0036] S50) The plate head is clamped by the outlet tension roller 10b, and the outlet guide plate 11b is lowered for winding to complete the second plate threading operation, which is equivalent to performing the plate threading operation by reversing through the outlet.

[0037] The proposed second plate-threading operation scheme is safe, reliable, and easy to operate, while not affecting the steel plate's production cost, product quality, or delivery time.

[0038] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0039] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for secondary piercing of a reciprocating rolling mill, characterized in that, The reciprocating mill is a six-roll reciprocating mill; The process includes the first and second threading. After the first threading is completed, the steel coil is cut in advance without achieving the predetermined number of passes, resulting in a pre-cut steel coil located on the inlet tension coil. The pre-cut steel coil is then threaded in the second process. The first piercing process involves feeding the steel coil from the tension reel of the uncoiler, piercing it from the tension reel of the uncoiler to the exit tension reel of the reciprocating mill for uncoiling pass rolling, and then piercing the steel coil that has been rolled from the uncoiling pass from the exit tension reel to the entrance tension reel of the reciprocating mill for reciprocating rolling. The second insertion of the plate includes at least the following steps: S10) Lift the pressing roller of the inlet tension roll to press down on the outer ring of the pre-cut steel coil; at the same time, open the roller gap of the work roll; S20) Clamp the head of the pre-cut steel coil and simultaneously jog the inlet tension reel, so that the pre-cut steel coil is conveyed in the direction of the outlet tension reel; S30) When the plate head reaches the roll gap of the work roll, a pressing force is applied to make the work roll clamp the plate head; S40) Simultaneously rotate the working roller and the inlet tension roller to lift the outlet guide plate so that the plate head reaches the outlet tension roller. S50) The plate head is clamped by the exit tension roller, and the exit guide plate is lowered for winding to complete the second plate threading operation.

2. The secondary piercing method for a reciprocating rolling mill according to claim 1, characterized in that, In step S10), before lifting the pressure roller of the inlet tension roll, the pins of the X-ray protection cover, scissors, pressure plate and pinch roll of the reciprocating mill are inserted to prevent mechanical injury to personnel caused by misoperation.

3. The secondary piercing method for a reciprocating rolling mill according to claim 1, characterized in that, In step S20), the head of the pre-cut steel coil is clamped with pliers.

4. The secondary piercing method for a reciprocating rolling mill according to claim 1, characterized in that, In step S30), the pressure is increased to 70-100 tons to ensure that the work roll clamps the plate head.

5. The secondary piercing method for a reciprocating rolling mill according to claim 1, characterized in that, The diameter of the inlet tension reel is smaller than the diameter of the uncoiler tension reel.

6. The secondary piercing method for a reciprocating rolling mill according to claim 5, characterized in that, The diameter of the inlet tension reel is 495-515mm.

7. The secondary piercing method for a reciprocating rolling mill according to claim 5, characterized in that, The diameter of the tension roll of the uncoiler is greater than 600 mm.

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