Straightening Machine Research Articles

A Method for Straightening Distorted Giga-Cast Large Thin-Walled Components.

Giga-casting, a revolutionary approach for manufacturing large, single-piece car body components from aluminium, has emerged as a potential game-changer in the automotive industry. However, these large, thin-walled castings are prone to distortions during solidification and heat treatment processes. Straightening these distortions is crucial to ensure structural integrity, facilitate downstream assembly, and maintain aesthetic qualities. This paper proposes a novel method for straightening giga-cast components using a multi-pin straightening machine. The machine's versatility stems from its ability to adapt to various geometries through multiple strategically controlled straightening pins. This paper introduces the concept of a "straightening stroke decision algorithm" to achieve precise straightening and overcome the challenges of complex shapes. This algorithm determines the stroke length for each pin, combining a polynomial model representing the global stiffness of the component with a machine learning model that captures the stiffness changes arising from the current geometry. The effectiveness of the proposed approach is evaluated through comprehensive numerical experiments using finite element analyses. The straightening performance is assessed for the straightening algorithm with different machine learning models (deep neural network and XGBoost) and compared to a traditional optimisation method. The proposed surrogate models decided the straightening strokes so that the maximum remaining distortion became 0.02% of the largest dimension of each target geometry. The results of the numerical experiment showed that the proposed straightening method is suitable for straightening distortion in large thin-walled components.

Integrated modeling for retired mechanical product genes in remanufacturing: A knowledge graph-based approach

Retired mechanical product genes refer to a collection of information that describes the structure, status, and related characteristics of retired mechanical products. Leveraging this information, along with its implicit knowledge, is a key approach to enhance the intelligence and efficiency of the remanufacturing process. This study aims to automatically obtain and integrate multi-source, heterogeneous, multilayer, and multidimensional retired mechanical product information and its implicit knowledge through a knowledge graph to form a gene bank, providing data basis for the remanufacturing process. First, the conceptual model of retired mechanical product genes and overall modeling framework based on knowledge graph are established. Next, according to the gene characteristics on different product layers, appropriate modeling methods were designed for part genes, product function and structure genes, product performance and failure genes respectively. For implicit rules and knowledge that pose challenges for direct representation, we express them in the IF-THEN form and convert them into triples. Then, an information fusion method is employed to integrate genes information on various layers into a gene graph. Finally, the proposed integrated modeling approach was evaluated in a scenario of remanufacturing an eleven-roll straightening machine. The results indicate that it can automatically obtain part genes information quickly and effectively. Additionally, it was confirmed that the constructed gene graph exhibits good accuracy and completeness, demonstrating the promising application prospects of the proposed method in remanufacturing.

Novel Straightening-Machine Design with Integrated Force Measurement for Straightening of High-Strength Flat Wire.

In a punch-bending machine, wire products are manufactured for a wide range of industrial sectors, such as the electronics industry. The raw material for this process is flat wire made of high-strength steel. During the manufacturing process of the flat wire, residual stresses and plastic deformations are induced into the wire. These residual stresses and deformations fluctuate over the length of the semi-finished product and have a negative effect on the final product quality. Straightening machines are used to reduce this influence to a minimum. So far, the adjustment of a straightening machine has been performed manually, which is a lengthy and complex task even for an experienced worker. This inevitably leads to the use of inefficient straightening strategies and causes high rejection rates in the entire production process. Due to a lack of sensor information from the straightening operation, application of modern feedback control methods has not been practicable. This paper presents a novel design for a straightening machine with an integrated, precise straightening force measurement. By simultaneously monitoring the position of the straightening rollers, state variables of the straightening operation can be derived. Additionally, a tension control for feeding the flat wire is introduced. This is implemented to mitigate the disturbing effects caused by irregularities in the wire-feeding process. In the results of this article, the high precision of the developed force measurement design and its possible applications are shown.

The Design of LabVIEW-based Measurement & Control System of Automatic Straightening Machine

With the development of the machinery industry and the popularization of shaft parts, the bending and deformation problems of shaft parts in the machining process have become particularly prominent. In order to reduce the bending deformation and improve the yield of parts, shaft straightening machines have become a necessary choice. According to the development status of straightening machines at home and abroad, and based on the consideration of improving the automation and intelligence level of domestic straightening machines, a fully automatic straightening machine measurement and control system has been proposed and developed in this paper based on the LabVIEW platform. It has been proved that the straightening machine can realize parallel operation of data in the working process, with high straightening accuracy and good operation stability.

STUDY OF THE ADDITIONAL POSSIBILITY EFFECT OF ELASTIC-PLASTIC ALTERNATING DEFORMATION ON THE PROPERTIES OF METAL MATERIALS DURING THEIR PROCESSING ON A ROLLER STRAIGHTENING MACHINE

The only way to increase the impact of elastic-plastic alternating bending on the properties and structure of metal materials is to go beyond the minimum input gap set by the nomogram from the operation manual of the EcoMaster®25 precision roller straightening machine. Analysis of the position of the working rollers when they are in contact and after the setting of a gap between them showed that within the limits of reducing the input gap by 30% from the boundary set by the nomogram, the possibilities of implementing the alteration process remain. Analytical dependences are constructed to determine the input gap for any values of the thickness of strips or sheets in the range from 1 to 3 mm, in which the distribution of the total equivalent intensity of the principal true strains is especially effective. The additivity of this magnitude of the deformation effect on metallic materials (along with the intensity of the principal true strains) is proved, which allows to consider it as a measure of the accumulated strain.

Safe contextual Bayesian optimization integrated in industrial control for self-learning machines

Intelligent manufacturing applications and agent-based implementations are scientifically investigated due to the enormous potential of industrial process optimization. The most widespread data-driven approach is the use of experimental history under test conditions for training, followed by execution of the trained model. Since factors, such as tool wear, affect the process, the experimental history has to be compiled extensively. In addition, individual machine noise implies that the models are not easily transferable to other (theoretically identical) machines. In contrast, a continual learning system should have the capacity to adapt (slightly) to a changing environment, e.g., another machine under different working conditions. Since this adaptation can potentially have a negative impact on process quality, especially in industry, safe optimization methods are required. In this article, we present a significant step towards self-optimizing machines in industry, by introducing a novel method for efficient safe contextual optimization and continuously trading-off between exploration and exploitation. Furthermore, an appropriate data discard strategy and local approximation techniques enable continual optimization. The approach is implemented as generic software module for an industrial edge control device. We apply this module to a steel straightening machine as an example, enabling it to adapt safely to changing environments.

Three-dimensional analysis of the stress-strain state for straightening pipes on skew-roll straightening machines with special roll profiling

In order to increase the competitiveness of domestic metal products, in particular pipes, it is necessary to ensure their compliance with international standards in terms of the main quality indicators. The pipe straightening process provides quality indicators such as straightness and cross-sectional shape. Skew-roll pipe straightening machines are the most common and most effective for straightening pipes of small and medium diameters. The most modern are six-roll pipe straightening machines with special roll profiling, which provide straightening of two types: in the caliber of the profiled rolls and at the step between the roll clamps. But the lack of knowledge about the regularities of straightening pipes holds back the wide implementation of such machines. In the work, a finite element model was developed and with its use, a study of the influence of the straightening process parameters in profiled rolls with symmetric and asymmetric profiling of the extreme pairs of rolls on the indicators of pipe straightness and straightening force was carried out. According to the results of their implementation, it was established that straightening the pipe in gauge and pitch allows to reduce the residual curvature of the pipe by almost three times with a 2.5 times smaller overlapping of the middle rolls relative to the outer ones. At the same time, the force on the most heavily loaded middle rolls increases almost twice, which should be taken into account in view of the possibility of ovality in the section of thin-walled pipes. The use of additional asymmetric profiling of the extreme rolls with step adjustment practically does not affect the quality of straightening in the gauge, increases the quality of straightening at the step by up to 15 %, while reducing the maximum straightening force by 5—7 %. The developed finite-element model allows determining the rational values of rolls overlaps to ensure the minimum residual curvature of the pipes.

Innovative Assistance System for Setting up a Mechatronic Straightening Machine

High-strength wire materials are usually available as strip material which is further processed in a forming process (e.g. punch-bending). For storage and transport of the semi-finished wire to the customer, the material is wound onto coils. The manufacturing and coiling process introduces plastic deformations into the wire, which lead to undesirable residual stresses and wire curvature of the semi-finished product. These residual stresses and curvatures cause variations in the material properties of the semi-finished product, which have a negative impact on the subsequent product quality. Straightening machines are used to compensate the residual stresses and the curvature in the wire. At the beginning of the straightening process, the straightening machines must be set up in such a way that residual stresses and curvatures are optimally compensated. This setup process is usually a manual and iterative process, where a lot of material is wasted until the optimal settings for the straightening machine are found.In order to reduce the amount of material waste, the operator must be supported in the setup process. In this context, a new and innovative setup assistance system was developed to support the operator during the setup process. The setup assistant system automatically detects the wire curvature by means of an optical measuring system. Based on the optically detected measuring points, the wire curvature is determined by a robust calculation algorithm. Based on a database built up through the carried out experimental and numerical research work, the optimum setting parameters for the straightening machine are suggested to the operator without lengthy trial and error. After confirmation by the operator, the roller settings are automatically adjusted by the mechatronic straightening machine. With the presented method, the conventional iterative setup procedure can be made more resource-efficient and a high straightening quality can be reproducibly achieved.

Study on cracks and process improvement for case hardened gear shaft straightening

Deformation of the gear shaft in transmission is inevitable after case hardened heat treatment. Straightening is the normal way to ensure the straightness requirement. During the straightening process, cracks often appear and result in scrapped parts. Based on the situation of high rejection rate of straightening crack of the internal input shaft of a dual-clutch automobile transmission, this paper makes an in-depth analyses of the pressure straightening process theory, the crack generation mechanism, the working process of the automatic straightening machine and the crack detection system, etc., and establishes the relationship between the ram increment, the total displacement and the crack rate during multi-step progressive straightening, proposes a way to quickly judge the straightening performance of the parts. Finally, after optimizing the pressure position by finite element analysis, optimizing the straightening procedure by adjusting ram increment and adopting vector straightening method, optimizing the parts martial properties by heat treatment improvement, the straightening crack rate of internal input shaft was reduced from 1.95 % to 0.14 %.

Geometric and Deformation Parameters of Elastoplastic Alternating Bending of a Strip during Processing on a Roller Straightening Machine

Geometric and Deformation Parameters of Elastoplastic Alternating Bending of a Strip during Processing on a Roller Straightening Machine

Mathematical model for calculating the parameters of straightening section profiles on a roller straightening machine

The analysis of the traditional theories of straightening section and shaped steel on a roller straightening machine (RSM) according to the methods of Korolev and Tselikov - Smirnov, using the linear law of change in the coefficient of penetration of plastic deformation along the height of the rolled product. It is shown that when straightening a steel angle 200 - 200 - 24 mm (σs = 440 MPa) on a nine-roller straightening machine (SM), the greatest discrepancy in the calculation of bending moments and straightening forces according to the Korolev and Tselikov - Smirnov methods is equal to 25 % and is observed on roller No. 4. A refined mathematical model is proposed to calculate the parameters of straightening of long products on the RSM. It provides a more accurate definition of the boundary between the elastic and plastic zones as a result of taking into account the bending hardening. On the basis of the developed model, an algorithm to calculate the straightening parameters of long products for an eight-roller SM of the universal rolling mill 650 of the Nizhniy Tagil Metallurgical Plant (NTMK) has been compiled. Comparative results of the calculated and experimental straightening forces for hardened rails 65R on the eight-roller SM of the plant are presented, confirming the adequacy of the developed model with an error of 20 %. The results of the study can be applied in calculating the parameters of straightening profiled sections, as well as in the modernization and design of RSM.

Research on the Design of a Hexagonal Shaft Straightening Machine Based on Quality Function Development and Evidence Theory

In response to the problem that weights in product planning and design are difficult to accurately reflect the real needs of users, a design method for hexagonal shaft straightening machines based on quality function configuration and evidence theory is proposed. First, based on the method of quality function deployment and evidence theory, the demand indicator and its importance are determined by market research and the Kano model. Second, to solve the conflict problem in the process of expert opinion aggregation, combined with evidence theory, taking expert knowledge as evidence, the possible value space of causal strength among nodes constitutes the recognition framework, which is used to synthesize the knowledge of multiple experts. The indicator correlation degree is reflected by using a correlation weight matrix, and effective solutions to the relevant theoretical problems and algorithms, such as those for competitive indicator evaluation, weight calculation and planning target value cases, are proposed. Finally, according to the analysis results for the various structural elements of the house of quality, a hexagonal shaft straightening machine function for master planning house of quality was constructed, and propose a design and build the main experimental platform. The relevant test results show that the technical specifications of the hexagonal shaft straightening machine basically meet the requirements of the overall planning target values, verifying the effectiveness and feasibility of the proposed method.

Innovative Measurement Of Stress Superposed Steel Strip For Straightening Machines

Higher quality requirements by customers demand higher precision and accuracy from manufacturing processes. Application oriented preparation of semi-finished materials is key for subsequent forming operations, therefore, straightening machines are employed. Straightening strengthens the material by increasing plastic deformation by means of strain hardening, resulting in undesirable reduction in formability when processing high strength materials, in particular. Conventional roll-type straightening machines process either bars or strips. This is achieved upon passing material between rolls arranged in two staggered rows. However, conventional straightening processes do not adapt to the local varying distortion of coiled strips. Innovative, self-correcting process control techniques, which adapt to the initial geometric characteristics of the strip, present a promising approach to fix this issue through optimization of the leveling process. Here, an innovative strategy to improve straightening of high strength steel materials (1.4310) is presented. This implements optimized leveling, adding minimal plastic deformation and, thus, strain hardening. To operate an intelligent straightening machine, a reliable online measurement of the surface defects is fundamentally essential. The MagnaTest, which is developed for material testing, is made feasible for such purposes after calibrating for curvature measurement. Preliminary results are promising in regards to measuring the curvature online, so that the following straightening process can be close loop controlled. The bending measurement is linked to open/closed loop control, therefore providing an optimal straightening result in regards to formability, leveling, and reduced strain hardening.

Development of modes for straightening of hot-rolled strip in order to obtain rolled products for high-tech processing

Modern requirements for the quality indicators of hot rolled sheet steel are associated with maintaining high flatness of sheet metal during further processing by high-tech methods, for example, by laser or plasma cutting. When laser cutting a sheet it may bend due to the release of residual stresses that are unevenly distributed over the volume. The final stage in the production of hot rolled steel is straightening on roller straightening machines under cyclic alternating deformation. The solution to the problem is the optimal control of residual stresses at the main final stage of hot rolled sheet production when straightening strips on roller levelers under cyclic alternating deformation. The existing numerous approaches of calculating the parameters of the straightening on roller straightening machines do not allow determining the optimal modes that eliminate the initial inhomogeneous stress state of the hot rolled strip and ensure the minimum level of residual stresses in the rolled product. The paper substantiates the relevance of developing a methodology for selecting a strip straightening mode, which provides an expansion of the possibilities of the straightening process on roller straightening machines and obtaining hot rolled sheets with a minimum level of residual stresses and potential energy, suitable for plasma and laser cutting. The article describes the implementation of the method for selecting the mode of hot rolled strip straightening process based on the results of finite element modeling, confi rmed by experimental data obtained during leveling and subsequent cutting of sheets. The modes of straightening of strips with a thickness of 4 mm, 8 mm and 10 mm of steel grade S355MC have been calculated on 13-, 15- and 17-roller straightening machines of Severstal, providing minimum residual stresses, potential energy in sheets after straightening and deviations from the flatness of sheets during high-tech cutting. Based on industrial tests, the method for calculating straightening modes was introduced into production, the developed modes were accepted for use at Severstal. The proposed improvements of technology of the production of hot rolled sheet metal in the conditions of Severstal made it possible to obtain products suitable for laser cutting.

Optimization Model of Process Parameters for Full-Plate Long-Roll Straightening considering Equipment Bounce

Roll straightening is an important process link in sheet production. Due to the step change of the straightening force during the straightening bite and the tail flick, the whole-plate length straightening and pressing process changes will affect the straightening effect. Based on the solution of the curvature integral straightening process, this paper introduces the stiffness coefficient of the straightening equipment. Through C language programming, the iterative solution has been realized, and the process parameters of the dynamic change of the straightening reduction have been obtained. The enumeration method was used to establish a calculation method to optimize the entire board-length straightening process. The laboratory comparison of the 11-roll straightening machine proves that the straightening process optimization model meets the application requirements.

Establishing the Strength Characteristics of the Lifting-Leveling Device Structures of the VPO-3-3000 Machines for the Track Straightening

This article deals with replacement of the magnetic grippers on the VPO-3-3000 machines with roller grippers. The novelty lies in establishment of dependences characterizing stress and strain in elements of the lifting and straightening devices and in rails during the operation. Reliability of the program for calculating the structural parameters of the lifting and straightening device for the VPO-3-3000 track renewal machine is shown. The developed design of the lifting and straightening device makes it possible to select the rational parameters of technology and the operating mode of the device. This design is recommended for use when developing working bodies for the straightening machines. The article presents calculation of the lifting and straightening device structural elements' strength during operation, in the Ansys WB software package.

Young Modulus at High Temperatures

The dependence of the young modulus of metals and alloys on the high temperature must be taken into account in metallurgy in the hot rolling of steel sheet on sheet-rolling mills, hot flattening of steel sheet in the sheet straightening machines, press forming forgings from hot steel sheet, hot volume stamping of metal products, and so on. For example, on the mill 5000 by SMS Siemag, the sheet-rolling of steel strips from the hot slabs at the stand Quarto (the maximum force of 120 MN) occurs at a temperature from 750 °С to 1050 °С, but the pre-flattening of hot steel strip on the five-roller sheet-straightening machine by SMS Siemag occurs usually in the temperature range from 600 °С to 760 °С. In this paper, based on the analysis of experimental data about the dependence of the young modulus for various steel alloys, the analytical dependence of the young modulus on temperature is obtained.

Working out of design procedure of sheet metal straightening parameters on roller-type straightening machine in rollers of different diameter

It is installed that non-uniform deviations from planeness of sheet different in magnitude, and also having negative and positive curvature at straightening on the traditional roller-type straightening machine, as rule, are not corrected, as the car has equal diameters of all working rollers which affects on planeness defect of sheet with equal curvature of rollers barrels. Dependences for calculation of roller radius and return bend angle are presented. It is shown that if the return bend angle is equal to initial bend angle of sheet at counter-camber the sheet is completely detected; if the return bend angle is less than initial bend angle of sheet return bend occurs partially, the sheet also is detected partially; if the return bend angle is more than initial bend angle of sheet the sheet is bent towards return bend. Dependences for calculation of powers of the editing spent for alternating bending of sheet, the power spent for friction of rolling motion of rollers on surface of sheet, the power spent for overcoming of frictional force on necks of carrying rollers in roller-type straightening machine with rollers of different diameters. Calculation of power consumption of the main drive electric motor at straightening of sheets from low-alloy steel for 5 —7-roller straightening machines with different diameters of rollers is presented. Difference between calculation results and the experiment data showed, difference makes 10...20 % that testifi es to adequacy of model and about possibility of its practical use for calculations of straightening parameters of sheet products on roller-type straightening machine with different diameters of rollers.

Determination of adjustment positive allowance at straightening of sheet metal on roller-type straightening machine

The designs analysis of roller-type straightening machine for sheet straightening showed that by positive allowance adjustment principle between machine rollers, two types are performed: with parallel and inclined rollers. Dependences for calculations of return bend curvature, adjusting positive allowance for parallel and inclined rollers roller-type straightening machine are presented. Pilot straightening is carrion on 7-roller straightening machine at straightening of sheets from 10 steel with thickness of 16 mm and width of 2400 mm. Comparison of results of the experimental value of positive allowance of 13.1 mm and the calculated value of 12.8 mm showed 4.5 % divergence.

Минимизация рисков показателей эксплуатации выправочно-подбивочнорихтовочных машин непрерывно-циклического действия

Минимизация рисков показателей эксплуатации выправочно-подбивочнорихтовочных машин непрерывно-циклического действия