Method for preventing blocking and breakage of a mill step pad

Abstract

The present application relates to the technical field of steel metallurgy rolling mill equipment, and particularly discloses a method for preventing jamming and breakage of a stepped pad under a rolling mill, wherein a spring with appropriate elasticity and height is installed in a stepped pad support frame to support the stepped pad; when the stepped pad is in a non-working position, there is a certain vertical gap between the stepped pad and the support frame and between the stepped pad and the pressure equalizing plate, so that the stepped pad can be smoothly moved above the pressure equalizing plate without jamming; when the stepped pad is in a working position and under a rolling force, the spring is compressed and deformed under stress, the gap between the stepped pad and the pressure equalizing plate is eliminated to contact and transmit the rolling force, and at this time, there is still a certain gap between the stepped pad and the support frame, so that the stepped pad is not suspended to bear and break; the method for preventing jamming and breakage of the stepped pad under the rolling mill ensures smooth roll changing and rolling mill calibration, reduces fault time and operation cost, and improves production operation rate.

Description

Technical Field

[0001] This invention relates to the field of steel metallurgical rolling mill equipment technology, specifically to a method for preventing jamming and breakage of the lower step pad of a rolling mill. Background Technology

[0002] To ensure the work roll elevation meets design requirements after multiple grinding and re-installation of the rolls in hot rolling mills and roughing and finishing mills, a lower step pad adjustment device is installed. This device calculates and adjusts the thickness of the step pad based on the diameter of the ground and re-installed rolls, ensuring the work roll surface elevation meets design requirements. For example, the lower step pad adjustment device in finishing mills F1-F7 has Step 1-Step 12 step pads, with a thickness of 100-265mm, increasing by 15mm with each step. Figure 1-2 As shown.

[0003] The F1-F7 finishing mill roll elevation adjustment calculation and control system calculates and determines the corresponding thickness of the step pads based on the diameter of the newly installed rolls. This information is then transmitted to the drive hydraulic cylinder 8, which drives the step pad support frame 2 to move laterally, moving the calculated step pads (such as Step 6) directly above the working position equalizing plate 7, thus completing the step pad adjustment. When not in the working position (i.e., not directly above the equalizing plate 7), each step pad (Step 1-Step 12) falls naturally onto the support frame 2 by gravity. Its lower surface elevation is 3mm lower than the upper surface of the equalizing plate 7. To ensure the step pads can smoothly move above the working position equalizing plate 7 when the support frame 2 moves laterally, transition chamfers are designed and machined on both sides of the lower surface of each step pad and the upper surface of the equalizing plate 7. This structural design utilizes a transition chamfer to allow the stepped pad (such as Step 6) to move laterally above the equalizing plate 7. At this time, the stepped pad (Step 6) is in the working position and is no longer in contact with the support frame 2. Its weight is borne by the equalizing plate 7. When the rolling force F is applied, the stepped pad (Step 6) in the working position transmits the rolling force load, while the support frame 2 does not bear the rolling force load.

[0004] As usage time increases, wear will occur on the contact surfaces of various components such as the step pad 1, support frame 2, and equalizing plate 7, leading to: First, an increase in the elevation difference between the lower surface of the step pad in the non-working position and the upper surface of the equalizing plate 7, causing the step pad to get stuck during lateral movement and unable to move normally above the equalizing plate 7, resulting in malfunctions and extended roll change time; Second, when the step pad (Step6) is directly above the equalizing plate 7 in the working position, the step pad (Step6) is still supported by the support frame 2, causing the lower surface of the step pad (Step6) to be suspended from the upper surface of the equalizing plate 7. When the rolling force F is applied, the suspended step pad will bear the load and break, and the equalizing plate 7 will also fail to bear the force normally, affecting the transmission and calibration of rolling force.

[0005] Existing technical methods and disadvantages: In order to enable Step1-Step12 to move smoothly to the top of the equalizing plate 7 during adjustment, the step pads (such as Step6) in the working position when the rolling force F is applied transmit the rolling force while the support frame 2 is not stressed. The elevation of the lower surface of each step pad in the non-working position is 3mm lower than the upper surface of the equalizing plate 7. The lower surface of each step pad and the upper surface of the equalizing plate 7 are designed and machined with transition chamfers on both sides. However, with prolonged use, wear will occur on the contact surfaces of various components such as the step pads 1, support frames 2, and equalizing plates 7, leading to: First, an increase in the elevation difference between the lower surface of the step pad in the non-working position and the upper surface of the equalizing plate, causing the step pad to become stuck and unable to move normally onto the equalizing plate during lateral movement, resulting in equipment failure and extended roll change time; Second, when the step pad (such as Step 6) is above the equalizing plate in the working position, the step pad and support frame are not in contact, causing the lower surface of the step pad to be suspended from the upper surface of the equalizing plate. When the rolling force F is applied, the suspended step pad will bear the load and break, and the equalizing plate will not be able to bear the force normally, affecting the transmission and calibration of rolling force.

[0006] Therefore, there is an urgent need to design a method to prevent the step pads under the rolling mill from jamming and breaking, in order to solve the technical problems of existing step pads jamming during lateral adjustment and breaking due to suspension when rolling force is applied. Summary of the Invention

[0007] To address the problems existing in the prior art, the present invention aims to provide a method for preventing jamming and breakage of the lower step pad of a rolling mill. This method solves the technical problems of jamming during the adjustment of the lateral movement of the step pad in the roughing and finishing mills of hot rolling lines, and breakage due to suspension when rolling force is applied. It ensures smooth roll changing and mill calibration, reduces downtime and operating costs, and improves production efficiency.

[0008] The technical solution adopted by this invention to solve its technical problem is: a method for preventing jamming and pressure breakage of the lower step pad of a rolling mill, comprising the following steps:

[0009] 1) For the F1-F7 finishing mill, select the appropriate model of spring support for each step pad according to the weight of each step pad in Step1-Step12;

[0010] 2) Drill holes at the positions where each step pad is placed on the step pad support frame, and place springs in the holes;

[0011] 3) When the stepped pad is in a non-working position, the lower surface of the stepped pad is higher than the upper surface of the equalizing plate, with a height difference H0 = 2-3 mm;

[0012] 4) When the stepped pad is in the working position, the rolling force F is applied to the stepped pad, causing the compression spring to deform. The stepped pad comes into contact with the pressure equalizing plate, and the height difference H1 between the lower surface of the stepped pad and the upper surface of the pressure equalizing plate is 0mm.

[0013] Specifically, the lower step pad adjustment device of the F1-F7 finishing mill in step 1) is equipped with 12 step pads, from Step 1 to Step 12.

[0014] Specifically, in step 1), the support springs of each step pad have the same spring force, height, and diameter. Each step pad is supported by four springs, with two springs on each side of the step pad. The deformation of the springs after bearing the weight of the step pad is within 1mm.

[0015] Specifically, in step 2), the position and number of holes on the stepped pad support frame are adapted to the spring, and the height of the spring extending out of the hole is h0 = 6-7 mm.

[0016] Specifically, when the step pad in step 4) is in the working position, there is still a gap h1=3mm between the step pad and the support frame, so that it is not suspended and crushed.

[0017] The present invention has the following beneficial effects:

[0018] The present invention designs a method for preventing jamming and breakage of the lower step pad in a rolling mill. Appropriate springs with suitable elasticity, height, and diameter are installed within the step pad support frame, supporting each stage of the step pad. When the step pad is in its non-working position, there are vertical gaps between the step pad and the support frame, and between the step pad and the equalizing plate, ensuring that the step pad can move smoothly above the equalizing plate without jamming during adjustment. When the step pad is in its working position, the rolling force is applied, compressing the springs to eliminate the gaps between the step pad and the equalizing plate, thus transmitting the rolling force. A certain gap still exists between the step pad and the support frame, ensuring that the step pad is not suspended and broken, thus ensuring smooth roll changes and mill calibration, reducing downtime and operating costs, and improving production efficiency. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the lower step adjustment device of the F1-F7 finishing mill.

[0020] Figure 2 yes Figure 1 Sectional view along the AA direction.

[0021] Figure 3 This is a schematic diagram of an embodiment of the anti-jamming and anti-breakage method for the lower step pad of the rolling mill.

[0022] Figure 4 This is a side view of an embodiment of the anti-jamming and anti-breakage method for the lower step pad of the rolling mill.

[0023] Figure 5 This is a schematic diagram of the structure of the lower step pad of the rolling mill when the rolling force F is applied.

[0024] In the diagram: 1 - Step 1-Step 12 step pad; 2 - Step pad support frame; 3 - Side liner; 4 - Flat liner; 5 - Spring; 6 - Support frame bracket; 7 - Pressure equalizing plate; 8 - Support frame drive hydraulic cylinder; F - Rolling force. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0026] like Figure 3-5 As shown, a method for preventing jamming and breakage of a step pad under a rolling mill is described. A spring 5 with appropriate elasticity and height is designed and installed within the step pad support frame 2, supporting the step pad 1. When the step pad 1 is in a non-working position, there are certain vertical gaps between the step pad 1 and the step pad support frame 2, and between the step pad 1 and the pressure equalizing plate 7, ensuring that the step pad 1 can move smoothly above the pressure equalizing plate 7 without jamming during adjustment. When the step pad 1 is in the working position and under the applied rolling force F, the spring 5 is compressed and deformed, eliminating the gap between the step pad 1 and the pressure equalizing plate 7, allowing them to contact and transmit the rolling force F. At this time, a certain gap still exists between the step pad 1 and the step pad support frame 2, ensuring that the step pad 1 does not suspend under load and breakage.

[0027] Example 1

[0028] A method for preventing jamming and breakage of the lower step pad in a rolling mill includes the following steps:

[0029] 1. The lower step pad adjustment device of the F1-F7 finishing mill is equipped with 12 steps 1 from Step 1 to Step 12. According to the weight of each step pad 1 from Step 1 to Step 12, a suitable spring 2 is selected to support each step pad 1. The spring force, height and diameter of each step pad are the same. Each step pad is supported by four springs, with two springs on each side of the step pad. The deformation of the spring after bearing the weight of the step pad is within 1mm.

[0030] 2. Drill holes in the step pad support frame 2 at the position of each step pad 1, two holes on each side. The position and number of holes on the step pad support frame 2 are adapted to the spring 5. The spring 5 is placed in the hole, and the height of the spring extending out of the hole is h0=6-7mm.

[0031] 3. When the step pad is in the non-working position, the lower surface of the step pad is higher than the upper surface of the pressure equalizing plate, with a height difference H0=2-3mm; to ensure that the step pad can be smoothly moved above the pressure equalizing plate without getting stuck when adjusting the horizontal movement.

[0032] 4. When the stepped pad is in the working position, the rolling force F is applied to the stepped pad, causing the compression spring to deform. The stepped pad contacts the pressure equalizing plate. The height difference H1 between the lower surface of the stepped pad and the upper surface of the pressure equalizing plate is 0mm. There is also a gap h1=3mm between the stepped pad and the support frame, so it will not be suspended and crushed.

[0033] This invention is not limited to the above-described embodiments. Anyone should know that any structural changes made under the guidance of this invention, and any technical solutions that are the same as or similar to this invention, fall within the protection scope of this invention.

[0034] The technologies, shapes, and structures not described in detail in this invention are all known technologies.

Claims

1. A method for preventing jamming and breakage of a mill step pad, characterized in that, It comprises the following steps: 1) F1-F7 finishing mill group selects the appropriate type of spring to support each step pad according to the weight of Step1-Step12 each step pad; the spring force, height and diameter of each step pad are consistent, each step pad is supported by four springs, two springs on the left and right sides of the step pad, and the deformation of the spring after bearing the weight of the step pad is within 1mm; 2) The step pad support frame is placed at the position of each step pad, and the spring is placed in the hole; the position and number of holes on the step pad support frame are matched with the spring, and the height of the spring extending out of the hole is h0=6-7mm; 3) When the step pad is in the non-working position, the lower surface of the step pad is higher than the upper surface of the pressure plate, and the height difference H0=2-3mm; 4) When the step pad is in the working position, the rolling force F is applied to the step pad, the compressed spring is deformed, the step pad is in contact with the pressure plate, the height difference between the lower surface of the step pad and the upper surface of the pressure plate is H1=0mm, and there is still a gap h1=3mm between the step pad and the support frame, so that the step pad does not hang and is not broken.

2. The method of jamming prevention and breakage of the mill step-down pad according to claim 1, characterized in that, The lower step pad adjusting device of the F1-F7 finishing mill group in the step 1) is provided with Step1-Step12, a total of 12 step pads.

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