Error monitoring method for large thickness steel structure straightening and polishing process

Abstract

The application discloses a kind of error monitoring methods of large thickness steel structure straightening polishing process, comprising the following steps: step S1, the roll gap of pre-straightening machine is adjusted, after pre-straightening is completed, it is cooled in cooling mechanism, then pre-straightening is carried out again;Step S2, after cooling, continue to open pre-straightening machine, and straightening is carried out;Step S3, thick steel plate structure is horizontally entered between the two cutting discs of polisher, and polishing is carried out;Step S4, the actual three-dimensional coordinates of each detection point are measured using three-dimensional laser ranging technology, the actual space point cloud of thick steel plate structure is formed, the characteristic line and characteristic surface of thick steel plate structure are constructed according to the theoretical space point cloud and actual space point cloud of thick steel plate structure, and analysis and comparison are carried out, the process of the application can guarantee the high-quality straightening polishing of thick steel plate, and three-dimensional laser ranging technology is used to measure the straight line of steel structure product, compared with traditional single-line two-dimensional detection technology, the method can carry out three-dimensional detection to steel structure, and is more accurate.

Description

Technical Field

[0001] This invention relates to the field of straightening and grinding processes for thick steel plate structures. More specifically, this invention relates to an error monitoring method for straightening and grinding processes of large-thickness steel structures. Background Technology

[0002] Thick steel plate structures are raw materials for many downstream products, and their quality has an immeasurable impact on the quality assurance of subsequent downstream products. The production process of thick steel plates is a large-scale and complex process involving many large machines. Problems in any link can lead to product quality issues or even the shutdown of the entire production line, greatly affecting product quality, production efficiency, and corporate economic benefits. In order to ensure the flatness of the steel plate before cooling, precision-rolled thick steel plate structures undergo a series of operations, such as straightening and grinding. After preparation, it is necessary to monitor the straightening and grinding errors. Conventional monitoring methods use laser gratings for single-line two-dimensional detection, which often results in large errors. Summary of the Invention

[0003] To achieve these objectives and other advantages according to the present invention, a preferred embodiment of the present invention provides an error monitoring method for the straightening and grinding process of a thick steel structure, wherein the straightening process utilizes a pre-straightening machine, a cooling mechanism, a straightening machine, and a grinding machine, the straightening machine being located between the cooling mechanism and the grinding machine, and the thick steel plate structure straightening and straightening error monitoring process includes the following steps:

[0004] Step S1: Adjust the roll gap of the pre-straightening machine to be greater than the maximum difference between the upper and lower surfaces of the thick steel plate structure to be straightened. The thick steel plate structure to be straightened moves forward until its front end enters the front side of the upper and lower rollers of the pre-straightening machine. At this time, adjust the roll gap of the pre-straightening machine, start the pre-straightening machine, and perform pre-straightening. After the pre-straightening is completed, it enters the cooling mechanism for cooling.

[0005] Step S2: After cooling is complete, continue to control the thick steel plate structure to be straightened to move forward until its front end enters the front side of the upper and lower rollers of the straightening machine, and start the pre-straightening machine to straighten it;

[0006] Step S3: The thick steel plate structure, which has been straightened in step S2, is horizontally placed between the two cutting discs of the grinding machine. The grinding machine is turned on. The two cutting discs are horizontally spaced vertically, and the space between them is used to place the thick steel plate structure. The two cutting discs rotate under the drive of the power mechanism, and the cutting disc located above presses down on the thick steel plate structure during the rotation.

[0007] Step S4: Set three-dimensional spatial coordinates. Select and determine several measurement points on the thick steel plate structure, and determine the theoretical three-dimensional coordinates of all measurement points on the thick steel plate structure in conjunction with the design drawings to form a theoretical spatial point cloud of the thick steel plate structure. Then, use three-dimensional laser ranging technology to measure the actual three-dimensional coordinates of each detection point to form an actual spatial point cloud of the thick steel plate structure. Construct feature lines and feature surfaces of the thick steel plate structure based on the theoretical spatial point cloud and the actual spatial point cloud, and analyze and compare them. If the two are consistent, it is qualified; otherwise, it is unqualified.

[0008] Preferably, in another embodiment, the pre-straightening machine is disposed within a semi-sealed housing, the semi-sealed housing comprising an upper housing and a lower housing, the lower end of the upper housing being open, the upper housing and the lower housing being open at the upper end, the upper housing and the lower housing being spaced apart vertically, the openings of the two housings being interconnected vertically, heating devices being installed in both the upper housing and the lower housing to heat the spaces within the upper housing and the lower housing respectively, and the distance between the upper housing and the lower housing being greater than the thickness of the steel plate to be straightened to allow the steel plate to enter, and the upper roller of the pre-straightening machine being located within the upper housing, and the lower roller of the pre-straightening machine being located within the lower housing.

[0009] Preferably, in another embodiment, a heat insulation layer is horizontally provided on the contact plane between the upper shell and the lower shell, and an opening is provided in the middle of the heat insulation layer for placing the straightening machine inside.

[0010] Preferably, in another embodiment, the pre-straightening in step S1 specifically includes the following operations: a first forward pre-straightening; after the forward straightening is completed, controlling the reaction movement of the thick steel plate structure to be straightened to perform reverse pre-straightening; a second reverse straightening; then controlling the reaction movement of the thick steel plate structure to be straightened to perform forward straightening; a third reverse pre-straightening; after the thick steel plate structure passes through the pre-straightening machine, it enters the cooling mechanism for cooling.

[0011] Preferably, in another embodiment, during the entire pre-straightening process of step S1, the temperature inside the upper housing is maintained at 800-950°C, the temperature inside the lower housing is maintained at 750-850°C, and the temperature inside the upper housing is always higher than the temperature inside the lower housing, with the temperature difference between the two maintained at 50-80°C.

[0012] Furthermore, during the pre-straightening process in step S1 and the straightening process in step S2, the conveying speed of the thick steel plate structure is controlled at 1.5 m / s.

[0013] Preferably, in another embodiment, the cutting disc is flat, and in step S3, during the grinding process, coolant needs to be sprayed onto both the upper and lower surfaces of the thick steel plate structure, with the upper and lower cutting discs rotating in opposite directions.

[0014] Preferably, in another embodiment, in step S3, during the grinding process, the rotational speed of the upper cutting disc is less than that of the lower cutting disc, and the difference in rotational speed between the two is maintained at 30-50 r / min.

[0015] Preferably, in another embodiment, during the grinding process, when the rotational speed of the two cutting discs increases uniformly to the first rotational speed, it is maintained at T1; when the rotational speed of the two cutting discs continues to increase uniformly to the second rotational speed, it is maintained at T2; when the rotational speed of the two cutting discs continues to increase uniformly to the third rotational speed, it is maintained at T3.

[0016] Preferably, in another embodiment, if the condition is not met, the controller will activate an alarm notification.

[0017] Preferably, in another embodiment, in step S1, the roll gap of the pre-straightener during the first forward pre-straightening is 1.08 times the ideal thickness of the thick steel plate structure; during the second reverse pre-straightening, the roll gap of the pre-straightener is 1.04 times the ideal thickness of the thick steel plate structure; and during the third forward pre-straightening, the roll gap of the pre-straightener is 1 time the ideal thickness of the thick steel plate structure.

[0018] The present invention has at least the following beneficial effects: the process of the present invention can ensure high-quality straightening and grinding of thick steel plates, and finally the straightness of steel structure products is measured by three-dimensional laser ranging technology. Compared with the traditional single-line two-dimensional detection technology, the detection method of this embodiment can perform three-dimensional detection of steel structures, which is more accurate.

[0019] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the installation of the pre-straightening machine in the semi-sealed housing in this invention. Detailed Implementation

[0021] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0022] The following description is intended to disclose the present invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious modifications will occur to those skilled in the art. The basic principles of the invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the invention.

[0023] Those skilled in the art should understand that, in the disclosure of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting this invention.

[0024] It is understood that the term "a" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple, and the term "a" should not be understood as a limitation on the number.

[0025] like Figure 1 As shown, a preferred embodiment of the present invention provides an error monitoring method for the straightening and grinding process of a thick steel structure. The straightening process utilizes a pre-straightening machine, a cooling mechanism, a straightening machine, and a grinding machine. The straightening machine is located between the cooling mechanism and the grinding machine. The straightening error process utilizes a laser grating and a controller. The process for straightening the thick steel plate structure and monitoring the straightening error includes the following steps:

[0026] Step S1: Adjust the roller gap of the pre-straightening machine to be greater than the maximum difference between the upper and lower surfaces of the thick steel plate structure to be straightened. The thick steel plate structure to be straightened moves forward until its front end enters the front side of the upper and lower rollers of the pre-straightening machine. At this time, adjust the roller gap of the pre-straightening machine, start the pre-straightening machine, and perform pre-straightening. The pre-straightening specifically includes the following operations: First forward pre-straightening; after the forward straightening is completed, control the reaction movement of the thick steel plate structure to be straightened to perform reverse pre-straightening, perform the second reverse straightening, and then control the reaction movement of the thick steel plate structure to be straightened to perform forward straightening, perform the third reverse pre-straightening. After the thick steel plate structure passes through the pre-straightening machine, it enters the cooling mechanism for cooling.

[0027] Step S2: After cooling is complete, continue to control the thick steel plate structure to be straightened to move forward until its front end enters the front side of the upper and lower rollers of the straightening machine, and start the pre-straightening machine;

[0028] Step S3: The thick steel plate structure, which has been straightened in step S2, is horizontally placed between the two cutting discs of the grinding machine. The grinding machine is turned on. The two cutting discs are horizontally spaced vertically, and the space between them is used to place the thick steel plate structure. The two cutting discs rotate under the drive of the power mechanism, and the cutting disc located above presses down on the thick steel plate structure during the rotation.

[0029] Step S4: Set three-dimensional spatial coordinates. Select and determine several measurement points on the thick steel plate structure, and determine the theoretical three-dimensional coordinates of all measurement points on the thick steel plate structure in conjunction with the design drawings to form a theoretical spatial point cloud of the thick steel plate structure. Then, use three-dimensional laser ranging technology to measure the actual three-dimensional coordinates of each detection point to form an actual spatial point cloud of the thick steel plate structure. Construct feature lines and feature surfaces of the thick steel plate structure based on the theoretical spatial point cloud and the actual spatial point cloud, and analyze and compare them. If the two are consistent, it is qualified; otherwise, it is unqualified.

[0030] In the above implementation scheme, the thick steel plate structure is first pre-straightened using a pre-straightening machine. To improve the straightening effect and accuracy, three straightening operations are performed in both forward and reverse directions. After pre-straightening, the plate is cooled before straightening. Following straightening, grinding is carried out to ensure the upper and lower surfaces of the thick steel plate structure are flush. This entire process ensures high-quality straightening and grinding of the thick steel plate. Finally, three-dimensional laser ranging technology is used to measure the straightness of the steel structure product. Compared to traditional single-line two-dimensional inspection technology, the inspection method in this implementation scheme can perform three-dimensional inspection of the steel structure, which is more accurate.

[0031] During the grinding process, two cutting discs are used simultaneously to grind both sides of the thick steel plate structure, which is more efficient.

[0032] During the rolling process, steel plates are mostly placed directly on a support frame. This leads to uneven cooling rates between the upper and lower surfaces of the steel plate, resulting in uneven temperature distribution and consequently, uneven stress distribution between the upper and lower surfaces. Therefore, in this embodiment, the temperature of the upper and lower surfaces of the thick steel plate structure is controlled to differ during the pre-straightening process. This is combined with different temperatures during the straightening process to release uneven stress and achieve final equilibrium. Specifically, the pre-straightening machine is housed within a semi-sealed housing, which includes an upper housing 110 and a lower housing 120. The lower end of the upper shell 110 is open, and the upper end of the lower shell 120 is open. The upper shell 110 and the lower shell 120 are spaced apart vertically, and their openings are connected vertically. Heating devices are installed inside both the upper shell 110 and the lower shell 120 to heat the spaces inside the upper shell 110 and the lower shell 120, respectively. The distance between the upper shell 110 and the lower shell 120 is greater than the thickness of the steel plate to be straightened, so that the steel plate to be straightened can enter. The upper roller 200 of the pre-straightening machine is located inside the upper shell 110, and the lower roller 300 of the pre-straightening machine is located inside the lower shell 120.

[0033] The heating device inside the upper shell 110 heats the space inside the upper shell, and the heating device inside the lower shell 120 heats the space inside the lower shell. By controlling the power of the two heating devices to be different, the temperature of the two spaces is controlled to be different. In order to achieve precise temperature control, temperature sensors are installed in the two spaces respectively to detect the temperature inside the space.

[0034] In another embodiment, a heat insulation layer 130 is horizontally provided on the contact plane between the upper housing 110 and the lower housing 120, and an opening is provided in the middle of the heat insulation layer for placing the straightening machine inside.

[0035] This can better prevent the temperatures of the upper housing 110 and the lower housing 120 from affecting each other, and achieve better control of the different temperatures of the two spaces.

[0036] Preferably, in another embodiment, during the entire pre-straightening process of step S1, the temperature inside the upper shell is maintained at 800-950°C, the temperature inside the lower shell is maintained at 750-850°C, and the temperature inside the upper shell is always higher than the temperature inside the lower shell, with the temperature difference between the two maintained at 50-80°C. By utilizing the temperature difference, different stresses are released to maintain stress balance.

[0037] In another embodiment, during the pre-straightening process in step S1 and the straightening process in step S2, the conveying speed of the thick steel plate structure is controlled at 1.5 m / s.

[0038] In another embodiment, the cutting disc is flat, and in step S3, during the grinding process, coolant needs to be sprayed onto both the upper and lower surfaces of the thick steel plate structure. The cutting discs located above and below rotate in opposite directions.

[0039] The grinding process of thick steel plate structures generates a large amount of heat, requiring the addition of coolant for cooling. The two cutting discs rotate in opposite directions because this results in opposite shearing forces, which helps maintain the balance and stability of the thick steel plate structure during grinding.

[0040] During the grinding process in step S3, the upper cutting disc maintains downward pressure on the thick steel plate structure. If the rotation speeds of the two cutting discs are the same, a problem arises: with identical speeds, the lateral frictional resistance generated by both cutting discs on the thick steel plate structure during rotation is the same. However, because the upper surface of the thick steel plate structure receives downward pressure from the upper cutting disc, the lateral frictional force on the upper surface increases. This results in uneven frictional resistance between the upper and lower surfaces of the thick steel plate structure, inevitably leading to uneven grinding and a reduction in quality. To achieve balanced grinding of both sides of the thick steel plate structure, the rotation speed of the upper cutting disc needs to be controlled to be lower than that of the lower cutting disc. Experiments have shown that maintaining a speed difference of 30-50 r / min between the two results in even and fine grinding.

[0041] In another embodiment, during the grinding process, when the rotational speeds of the two cutting discs increase uniformly to the first rotational speed, the speed is maintained at T1; when the rotational speeds of the two cutting discs continue to increase uniformly to the second rotational speed, the speed is maintained at T2; and when the rotational speeds of the two cutting discs continue to increase uniformly to the third rotational speed, the speed is maintained at T3. Compared to single-stage grinding, step-by-step grinding results in a finer finish.

[0042] In another embodiment, in step S4, if the laser grating detects that the distance exceeds a preset value, the controller will activate an alarm.

[0043] In another embodiment, in step S1, the roll gap of the pre-straightener during the first forward pre-straightening is 1.08 times the ideal thickness of the thick steel plate structure; during the second reverse pre-straightening, the roll gap of the pre-straightener is 1.04 times the ideal thickness of the thick steel plate structure; and during the third forward pre-straightening, the roll gap of the pre-straightener is 1 time the ideal thickness of the thick steel plate structure.

[0044] In the above implementation plan, considering that the thick steel plate structure may have large straightness deformation before treatment, it is necessary to pre-straighten it in multiple stages, generally three times. During the three pre-straightening processes, the roller gap is gradually reduced to straighten the thick steel plate structure step by step, so as to avoid the stress change of the thick steel plate structure with large deformation caused by a single straightening, which could lead to fracture cracks.

[0045] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. An error monitoring method for the straightening and grinding process of thick steel structures, wherein, The straightening process utilizes a pre-straightening machine, a cooling mechanism, a straightening machine, and a grinding machine, with the straightening machine located between the cooling mechanism and the grinding machine. The method is characterized by the following steps: Step S1: Adjust the roll gap of the pre-straightening machine to be greater than the maximum difference between the upper and lower surfaces of the thick steel plate structure to be straightened. The thick steel plate structure to be straightened moves forward until its front end enters the front side of the upper and lower rollers of the pre-straightening machine. At this time, adjust the roll gap of the pre-straightening machine, start the pre-straightening machine, and perform pre-straightening. After the pre-straightening is completed, it enters the cooling mechanism for cooling. Step S2: After cooling is complete, continue to control the thick steel plate structure to be straightened to move forward until its front end enters the front side of the upper and lower rollers of the straightening machine, and start the pre-straightening machine to straighten it; Step S3: The thick steel plate structure, which has been straightened in step S2, is horizontally placed between the two cutting discs of the grinding machine. The grinding machine is turned on. The two cutting discs are horizontally spaced vertically, and the space between them is used to place the thick steel plate structure. The two cutting discs rotate under the drive of the power mechanism, and the cutting disc located above presses down on the thick steel plate structure during the rotation. Step S4: Set three-dimensional spatial coordinates. Select and determine several measurement points on the thick steel plate structure, and determine the theoretical three-dimensional coordinates of all measurement points on the thick steel plate structure in conjunction with the design drawings to form the theoretical spatial point cloud of the thick steel plate structure. Then, use three-dimensional laser ranging technology to measure the actual three-dimensional coordinates of each detection point to form the actual spatial point cloud of the thick steel plate structure. Construct the feature lines and feature surfaces of the thick steel plate structure based on the theoretical spatial point cloud and the actual spatial point cloud, and analyze and compare them. If the two are consistent, it is qualified; otherwise, it is unqualified. The pre-straightening machine is housed in a semi-sealed shell, which includes an upper shell and a lower shell. The lower end of the upper shell is open, and the upper shell and the lower shell are open at the upper and lower ends, respectively. The upper shell and the lower shell are spaced apart vertically, and their openings are connected vertically. Heating devices are installed in both the upper shell and the lower shell to heat the spaces inside the upper shell and the lower shell, respectively. The distance between the upper shell and the lower shell is greater than the thickness of the steel plate to be straightened, so that the steel plate to be straightened can enter. The upper roller of the pre-straightening machine is located inside the upper shell, and the lower roller of the pre-straightening machine is located inside the lower shell. The space inside the upper shell is heated by a heating device inside the upper shell, and the space inside the lower shell is heated by a heating device inside the lower shell. By controlling the power of the two heating devices to be different, the temperature of the two spaces can be controlled to be different. The pre-straightening in step S1 specifically includes the following operations: The first forward pre-straightening is performed. After the forward straightening is completed, the reaction movement of the thick steel plate structure to be straightened is controlled to perform reverse pre-straightening. The second reverse straightening is performed. Then the reaction movement of the thick steel plate structure to be straightened is controlled to perform forward straightening. The third reverse pre-straightening is performed. After the thick steel plate structure passes through the pre-straightening machine, it enters the cooling mechanism for cooling. Throughout the pre-straightening process in step S1, the temperature inside the upper housing is maintained at 800-950℃, the temperature inside the lower housing is maintained at 750-850℃, and the temperature inside the upper housing is always higher than the temperature inside the lower housing, with the temperature difference between the two maintained at 50-80℃. Furthermore, during the pre-straightening process in step S1 and the straightening process in step S2, the conveying speed of the thick steel plate structure is controlled at 1.5 m / s. The cutting disc is flat. In step S3, during the grinding process, coolant needs to be sprayed onto both the upper and lower surfaces of the thick steel plate structure. The cutting discs located above and below rotate in opposite directions. In step S3, during the grinding process, the rotational speed of the upper cutting disc is less than that of the lower cutting disc, and the difference in rotational speed between the two is maintained at 30-50 r / min.

2. The error monitoring method for the straightening and grinding process of thick steel structures according to claim 1, characterized in that, A heat insulation layer is horizontally provided on the contact plane between the upper shell and the lower shell, and an opening is provided in the middle of the heat insulation layer to allow the straightening machine to be placed inside.

3. The error monitoring method for the straightening and grinding process of thick steel structures according to claim 1, characterized in that, Furthermore, during the grinding process, when the rotational speed of the two cutting discs increases uniformly to the first rotational speed, it is maintained at T1; when the rotational speed of the two cutting discs continues to increase uniformly to the second rotational speed, it is maintained at T2; when the rotational speed of the two cutting discs continues to increase uniformly to the third rotational speed, it is maintained at T3.

4. The error monitoring method for the straightening and grinding process of thick steel structures according to claim 1, characterized in that, In step S4, if the condition is not met, the controller will activate an alarm.

5. The error monitoring method for the straightening and grinding process of thick steel structures according to claim 1, characterized in that, In step S1, the roll gap of the pre-straightener during the first forward pre-straightening is 1.08 times the ideal thickness of the thick steel plate structure; the roll gap of the pre-straightener during the second reverse pre-straightening is 1.04 times the ideal thickness of the thick steel plate structure; and the roll gap of the pre-straightener during the third forward pre-straightening is 1 time the ideal thickness of the thick steel plate structure.

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