A method for improving the replacement speed of the piston components of the upper bending roll cylinder of a strip rolling mill

Abstract

The present invention discloses a method for improving the replacement speed of the piston component of the upper bending roll cylinder of a plate and strip rolling mill. The method provides stable and accurate positioning for the installation of the piston component by installing a support plate and a centering bolt. On the one hand, the piston mounting hole opened above the mounting support plate can firmly limit the piston component, and the centering bolts are connected and arranged between the mounting support plate and the lower end surface of the upper bending roll cylinder, which can provide a lifting path in the vertical direction for the mounting support plate, thereby preventing the piston component placed above the mounting support plate from shaking and hitting the bending roll cylinder during the lifting process; on the other hand, during the installation and replacement work, the piston mounting hole and the piston port on the lower end surface of the upper bending roll cylinder are coaxially arranged, thereby providing accurate positioning for the piston component and saving the centering time required during the lifting process. The present invention also uses different types of lifting devices to lift the mounting support plate and the piston rod respectively, thereby solving the problem of the heavy piston component.

Description

Technical Field

[0001] The invention relates to a maintenance method, in particular to a method for improving the replacement speed of a bending roll cylinder piston component on a plate and strip rolling mill. Background Art

[0002] Roll bending technology uses mechanical force to bend the roll barrel to control the crown and straightness of the strip. Since its introduction in the early 1960s, roll bending has developed rapidly, and roll bending devices have become essential equipment on various plate and strip mills. Work roll bending is generally used when the ratio of the work roll barrel length (L) to its diameter (D) (L / D) is less than 3.5.

[0003] Roll bending cylinders are a crucial component of the strip finishing mill. Typically, a strip mill train is equipped with dozens of these cylinders. They operate by applying a bending force to the work roll bearings. This force, generated by leveraging the two contact points between the work roll and the backup roll shoulder, bends the center section of the work roll upward. This bending of the work roll can significantly improve the profile of the rolled steel plate.

[0004] Since the upper bending roller cylinder is located at the lower end of the bending roller block, the working space available for installation and replacement is small, and the installation direction of the upper bending roller cylinder piston component needs to be close to the ground from bottom to top. At the same time, the piston component that needs to be replaced in the bending roller cylinder is heavy, which makes the installation more difficult and takes a long time.

[0005] A method is currently needed to increase the replacement speed of the upper bending roll cylinder piston component in a plate and strip rolling mill while ensuring a smooth lifting and assembly process of the piston component. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to address the deficiencies of the above-mentioned prior art and to provide a method for improving the replacement speed of the piston components of the upper bending roll cylinder of a strip rolling mill. The method for improving the replacement speed of the piston components of the upper bending roll cylinder of a strip rolling mill can improve the replacement speed of the piston components of the upper bending roll cylinder of a strip rolling mill, while ensuring a smooth lifting and assembly process of the piston components.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0008] A method for improving the replacement speed of a bending roll cylinder piston component of a plate and strip rolling mill comprises the following steps.

[0009] Step 1: Install the new piston component: The upper bending roller cylinder includes a piston port and an inner cavity of the bending roller cylinder; the piston component includes a piston end and a piston rod; the installation of the new piston component specifically includes the following steps.

[0010] Step 1A, align the piston components: insert the piston rod vertically downward into the piston mounting hole of the mounting support plate, and at the same time connect the upper ends of several centering bolts to the threaded holes corresponding to the lower end surface of the upper bending roller cylinder, and then pass the lower ends of several centering bolts through the corresponding bolt positioning holes on the mounting support plate, and tighten the nuts under the centering bolts to complete the assembly of the centering bolts and the mounting support plate.

[0011] Step 1B, lifting the piston end: Place two hydraulic lifting devices symmetrically on the left and right sides of the piston component, and the upper ends of the two hydraulic lifting devices are in contact with the lower surface of the mounting support plate. Then, drive the two hydraulic lifting devices synchronously to lift the mounting support plate upward. When the piston end completely enters the piston port of the upper bending roller cylinder and the upper surface of the mounting support plate is in contact with the lower end surface of the upper bending roller cylinder, stop the hydraulic lifting device to complete the lifting of the piston end.

[0012] Step 1C, piston rod lifting: Place the mechanical lifting device below the center of the lower surface of the piston rod, then drive the second hydraulic device to lift the piston rod and the piston end upward. When the piston rod is completely pushed into the inner cavity of the bending roll cylinder, stop the mechanical lifting device to complete the installation of the piston rod and the piston end.

[0013] In step 1A, a piston mounting hole and a bolt positioning hole are opened on the mounting support plate. The piston mounting hole is set at the center of the mounting support plate. The number of bolt positioning holes is set to N, where: N≥2; the N bolt positioning holes are all arranged along the circumference of the piston mounting hole.

[0014] In step 1A, the number of centering bolts is N, and the lower end surface of the upper bending roller cylinder is correspondingly provided with N threaded holes.

[0015] In step 1A, N bolt locating holes and N threaded holes are arranged in a one-to-one correspondence in the vertical direction.

[0016] In step 1B, the upper ends of the two hydraulic lifting devices are at the same height from the ground.

[0017] In step 1A, the distance between the lower end surface of the upper bending roller cylinder and the ground is l, the length of the centering bolt is l1, the length of the piston end is l2, the length of the piston rod is l3, and the length of the connecting thread on the centering bolt is l4, where: l1-l4+l3-h≤l-10cm, l1≤l2+l3, 10cm≤l1-l4-l2≤30cm, The material of the centering bolt is preferably 16Mn.

[0018] In step 1A, the distance between the piston mounting hole and the positioning bolt hole is a, the distance from the piston mounting hole to the short side of the mounting support plate is b, the distance from the piston mounting hole to the long side of the mounting support plate is c, the diameter of the positioning bolt hole is d1, the diameter of the piston mounting hole is d2, the diameter of the piston rod is d3, and the diameter of the upper end surface of the hydraulic lifting device is d4, where: a≥1.5d1, b≥d4+30cm, 1.05d3≤d2≤1.08d3.

[0019] The hydraulic lifting device is an oil hydraulic jack, and the mechanical lifting device is a scissor jack.

[0020] The material of the mounting support plate is 45 steel and the material of the centering bolt is 16Mn.

[0021] The present invention has the following beneficial effects:

[0022] 1. The present invention can provide stable and accurate positioning for the installation of the piston component through the installation support plate and the centering bolts. On the one hand, the piston mounting hole opened above the installation support plate can firmly limit the piston component, and the centering bolts are connected and arranged between the installation support plate and the lower end surface of the upper bending roller cylinder, which can provide a lifting path in the vertical direction for the installation support plate, thereby preventing the piston component placed above the installation support plate from shaking and hitting the bending roller cylinder during the lifting process; on the other hand, during the installation and replacement work, the piston mounting hole and the piston port on the lower end surface of the upper bending roller cylinder are coaxially arranged, thereby providing accurate positioning for the piston component and saving the centering time required for the piston component during the lifting process.

[0023] 2. Since the initial heights of the mounting plate and the piston rod before lifting are different, in order to save installation working space, the present invention mainly uses different types of lifting devices to lift the mounting plate and the piston rod respectively, thereby solving the problem of the heavy weight of the piston component. At the same time, the mounting plate and the centering bolt can also ensure that the piston component remains in a horizontal and stable state during the lifting work. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of an installation tool assembly for a method of improving the replacement speed of a bending roll cylinder piston component of a plate and strip rolling mill according to the present invention.

[0025] Figure 2 A top view of the mounting support plate of the present invention is shown.

[0026] Figure 3 Shows the installation schematic diagram of the upper bending roller cylinder in the present invention.

[0027] Figure 4 The standardized operation installation process of the present invention is shown.

[0028] Among them are:

[0029] 10. Upper bending roller cylinder; 11. Piston port; 12. Inner cavity of bending roller cylinder;

[0030] 20. Piston component; 21. Piston end; 22. Piston rod;

[0031] 30. Mounting plate; 31. Piston mounting hole; 32. Bolt positioning hole;

[0032] 40. Centering bolts;

[0033] 50. Hydraulic lifting device;

[0034] 60. Mechanical lifting device. DETAILED DESCRIPTION

[0035] The present invention will be further described in detail below with reference to the accompanying drawings and specific preferred embodiments.

[0036] In the description of the present invention, it should be understood that the terms "left side," "right side," "upper," "lower," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Terms such as "first" and "second" do not indicate the importance of components and therefore should not be construed as limitations on the present invention. The specific dimensions used in this embodiment are intended only to illustrate the technical solution and do not limit the scope of protection of the present invention.

[0037] The present invention is described in detail by taking the upper bending roll cylinder of the plate and strip finishing mill in the applicant's steel plate general plant as an example.

[0038] A method for improving the replacement speed of a bending roll cylinder piston component of a plate and strip rolling mill comprises the following steps.

[0039] Step 1: Install a new piston component: The upper bending roller cylinder 10 includes a piston port 11 and an inner cavity 12 of the bending roller cylinder; the piston component 20 includes a piston end 21 and a piston rod 22.

[0040] Bending cylinders are a crucial component of the strip finishing mill. A single strip mill unit is equipped with 56 of these cylinders. They operate by applying a bending force to the work roll bearings. This force, generated by leveraging the two contact points between the work roll and the backup roll shoulder, bends the center section of the work roll upward. This bending of the work roll significantly improves the profile of the rolled steel plate.

[0041] like Figure 4As shown, the present invention primarily relates to the replacement of the upper bending cylinder. The piston port of the upper bending cylinder points vertically downward, pushing the piston rod vertically downward and exerting a downward force on the work roll bearing seat. The upper bending cylinder is located at the lower end of the bending block, leaving a narrow working space for installation and replacement, typically 1 meter. Furthermore, the piston assembly must be installed from the bottom up, close to the ground, further increasing the installation difficulty. Furthermore, the piston assembly required for replacement is heavy, typically weighing 35 kg, making installation difficult and time-consuming.

[0042] The installation of the new piston assembly specifically includes the following steps:

[0043] Step 1A, align the piston components: insert the piston rod vertically downward into the piston mounting hole 31 of the mounting support plate 30, and at the same time connect the upper ends of several centering bolts 40 to the threaded holes corresponding to the lower end surface of the upper bending roller cylinder, and then pass the lower ends of several centering bolts through the corresponding bolt positioning holes 32 on the mounting support plate, and tighten the nuts under the centering bolts to complete the assembly of the centering bolts and the mounting support plate.

[0044] like Figure 1 、 Figure 2 and Figure 4 As shown, the mounting plate is provided with a piston mounting hole and a bolt positioning hole, and the piston mounting hole is provided at the center of the mounting plate. The number of bolt positioning holes is provided at N, where: N ≥ 2; the N bolt positioning holes are arranged circumferentially along the piston mounting hole. The number of centering bolts is also provided at N, and the lower end surface of the upper bending roller cylinder is provided with N threaded holes. The N bolt positioning holes and the N threaded holes are provided in a one-to-one correspondence in the vertical direction, thereby ensuring that each centering bolt remains in a vertical state after assembly is completed, providing a vertical lifting path for the mounting plate and accurate positioning for the piston component, thereby saving the centering time required for the piston component during the lifting process.

[0045] A limit nut is threadedly connected to the bottom of each centering bolt, and several limit nuts are located at the same height to ensure that the mounting support plate can remain horizontal when lifted to the lowest position, facilitating subsequent lifting work.

[0046] Step 1B, lifting the piston end: place two hydraulic lifting devices 50 symmetrically on the left and right sides of the piston component, and the upper ends of the two hydraulic lifting devices are in contact with the lower surface of the mounting support plate. Then, the two hydraulic lifting devices are synchronously driven to lift the mounting support plate upward. When the piston end completely enters the piston port of the upper bending roller cylinder and the upper surface of the mounting support plate is in contact with the lower end surface of the upper bending roller cylinder, the hydraulic lifting device is stopped to complete the lifting of the piston end.

[0047] Before lifting the piston end, the upper ends of the hydraulic lifting devices on the left and right sides of the piston assembly should be at the same height. Simultaneously, the two hydraulic lifting devices should be pushed upward synchronously until their upper end surfaces contact the lower surface of the mounting support plate, completing the pre-lift preparations. Since the piston assembly's lifting path is determined by the centering bolts, to ensure the mounting support plate remains horizontal during the vertical upward lifting of the piston assembly, the two hydraulic lifting devices should advance the same distance within the same timeframe to prevent friction between the mounting support plate and the centering bolts at the bolt locating openings, ensuring smooth lifting of the piston end.

[0048] Step 1C, piston rod lifting: Place the mechanical lifting device 60 below the center of the lower surface of the piston rod, then drive the hydraulic device 2 to lift the piston rod and the piston end upward. When the piston rod is completely pushed into the inner cavity of the bending roll cylinder, stop the mechanical lifting device to complete the installation of the piston rod and the piston end.

[0049] Since the initial heights of the mounting plate and the piston rod before lifting are different, in order to save installation working space, the present invention mainly uses different types of lifting devices to lift the mounting plate and the piston rod respectively.

[0050] The hydraulic lifting device is preferably a hydraulic jack, and the mechanical lifting device is preferably a scissor jack. Since the hydraulic jack is at a high height when it is in the lowered state, it is preferred to use a hydraulic jack to support and lift the mounting plate and keep the mounting plate balanced. Since the piston rod has been fully aligned in the early stages of the lifting work, only the mechanical lifting device is required to stably lift the piston rod into position, so a scissor jack is preferably used for lifting. The scissor jack has a low lowering height and a large contact area at the upper end, which is more suitable for lifting the piston rod.

[0051] Using hydraulic lifting devices and mechanical lifting devices to lift the piston component respectively can ensure the overall stability of the lifting work. The hydraulic lifting device mainly lifts and centers the piston end with the assistance of installing the support plate, and then uses the mechanical lifting device to completely lift the piston component into the inner cavity of the bending roller cylinder, thereby solving the problem of the large weight of the piston component. At the same time, installing the support plate and the centering bolt can also ensure that the piston component maintains a horizontal and stable state during the lifting work.

[0052] The mounting plate is primarily used to assist the hydraulic lifting device during the lifting of the piston end and to support the entire piston assembly. Because the centrally located piston assembly is relatively heavy, and both sides of the mounting plate are simultaneously supported by the upward force provided by the hydraulic lifting device, the mounting plate is subject to significant shear forces. Therefore, the mounting plate in the present invention is preferably made of 45 steel, which meets the requirements of a tensile strength of 600 MPa and a yield strength of 355 MPa. This high-quality steel offers superior strength, plasticity, and toughness compared to carbon structures, resulting in superior overall mechanical properties and convenient material sourcing and processing.

[0053] The total weight of the piston assembly is 35 kg, and the thickness h of the mounting support plate is 10 mm. Typically, the weight of piston components in a plate and strip rolling mill ranges from 20 kg to 200 kg. When the total weight of the piston assembly is G ≤ 50 kg, h = 10 mm; when it is 50 kg ≤ G ≤ 100 kg, h = 15 mm; and when it is 100 kg ≤ G ≤ 200 kg, h = 20 mm.

[0054] The centering bolt is mainly used to connect the mounting plate and the lower end face of the upper bending roller cylinder, and provide a vertical path for the mounting plate to be lifted. Let the distance from the lower end face of the upper bending roller cylinder to the ground be l, the length of the centering bolt be l1, the length of the piston end be l2, the length of the piston rod be l3, and the length of the connecting thread on the centering bolt be l4. Considering the limited installation space of the piston component and the stability of the piston component lifting work, it should meet the following conditions: l1-l4+l3-h≤l-10cm, l1≤l2+l3, 10cm≤l1-l4-l2≤30cm. The material of the centering bolt is preferably 16Mn.

[0055] like Figure 1 and Figure 2 As shown, when N is 2, a is the distance between the piston mounting hole and the locating bolt hole, b is the distance from the piston mounting hole to the short side of the mounting support plate, and c is the distance from the piston mounting hole to the long side of the mounting support plate. The diameter of the locating bolt hole is d1, the diameter of the piston mounting hole is d2, the diameter of the piston rod is d3, and the diameter of the upper end face of the hydraulic lifting device is d4. To ensure the stability of the piston component during lifting and the mechanical properties of the mounting support plate, the following conditions must be met: a ≥ 1.5d1, b ≥ d4 + 30cm, and 1.05d3 ≤ d2 ≤ 1.08d3.

[0056] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and these equivalent transformations all fall within the scope of protection of the present invention.

Claims

1. A method for increasing the replacement speed of the upper bending cylinder piston component of a strip rolling mill, characterized in that: The steps include: Step 1: Install the new piston component: The upper bending roller cylinder includes a piston port and an inner cavity of the bending roller cylinder; the piston component includes a piston end and a piston rod; the installation of the new piston component specifically includes the following steps: Step 1A, Piston component alignment: Insert the piston rod vertically downward into the piston mounting hole of the mounting support plate, and at the same time connect the upper ends of several centering bolts to the corresponding threaded holes on the lower end surface of the upper bending roller cylinder. Then, pass the lower ends of several centering bolts through the corresponding bolt positioning holes on the mounting support plate, and tighten the nuts under the centering bolts to complete the assembly of the centering bolts and the mounting support plate. Step 1B, lifting the piston end: symmetrically place two hydraulic lifting devices on the left and right sides of the piston component, with the upper ends of the two hydraulic lifting devices in contact with the lower surface of the mounting support plate. Then, synchronously drive the two hydraulic lifting devices to lift the mounting support plate upward. When the piston end completely enters the piston port of the upper bending roller cylinder and the upper surface of the mounting support plate is in contact with the lower end surface of the upper bending roller cylinder, stop the hydraulic lifting device, and the piston end is lifted; Step 1C, piston rod lifting: Place the mechanical lifting device below the center of the lower surface of the piston rod, then drive the mechanical lifting device to lift the piston rod and the piston end upward. When the piston rod is completely pushed into the inner cavity of the bending roll cylinder, stop the mechanical lifting device to complete the installation of the piston rod and the piston end.

2. The method for improving the replacement speed of the upper bending cylinder piston component of a strip rolling mill according to claim 1, characterized in that: In step 1A, a piston mounting hole and a bolt positioning hole are provided on the mounting support plate. The piston mounting hole is provided at the center of the mounting support plate, and the number of the bolt positioning holes is provided. N , of which: N 2; N The bolt positioning holes are arranged along the circumference of the piston mounting hole.

3. The method for improving the replacement speed of the upper bending cylinder piston component of a strip rolling mill according to claim 2, characterized in that: In step 1A, the number of centering bolts is set to N The lower end of the upper bending roller cylinder is provided with N threaded holes.

4. The method for improving the replacement speed of the upper bending cylinder piston component of a strip rolling mill according to claim 3, characterized in that: In step 1A, N Bolt positioning holes and N The threaded holes are arranged in a one-to-one correspondence in the vertical direction.

5. The method for improving the replacement speed of the upper bending cylinder piston component of a strip rolling mill according to claim 1, characterized in that: In step 1B, the upper ends of the two hydraulic lifting devices are at the same height from the ground.

6. The method for improving the replacement speed of the upper bending cylinder piston component of a strip rolling mill according to claim 1, characterized in that: The hydraulic lifting device is an oil hydraulic jack, and the mechanical lifting device is a scissor jack.

7. The method for improving the replacement speed of the upper bending cylinder piston component of a strip rolling mill according to claim 1, characterized in that: The material of the mounting support plate is 45 steel and the material of the centering bolt is 16Mn.

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