Horizontal Lathe Research Articles

Modeling the dynamic interaction between machine tools and their foundations

The performance of a machine tool is directly influenced by the characteristics of the floor, subsoil, and their interaction with the installed machine. Installing a machine tool in its operational environment poses a distinct challenge that bridges mechanical and civil engineering disciplines. This interdisciplinary issue is often overlooked within the individual separate disciplines. However, effectively addressing this challenge requires a comprehensive understanding of mechanical and civil engineering principles. To address this problem, the present study proposes a method for improved modeling of the dynamic properties of the machine tool by considering the foundation and the subsoil on which it is installed. The method is based on finite element modeling. Linear models of the system components and the connections between them were used. These, supplemented with damping expressed by complex stiffness, made it possible to determine the natural frequencies, mode shapes, and frequency response functions (based on which the transmissibilities were obtained). Based on the experimentally verified models of vertical and horizontal lathes, the sensitivity analysis aimed at estimating the impact of changes in system parameters on vibration transmissibility for a floor-type and a block-type foundation was conducted. Thus, it was possible to identify those machine tool-support-foundation-subsoil system parameters that had the most significant impacts on the vibration's transmissibility. After analyzing the cases discussed, it became evident that the transmissibility of vibrations is primarily influenced by two key factors. First and foremost, the properties of the structural loop of the machine tool played a significant role. Additionally, the characteristics of the subsoil on which the foundation was situated emerged as a crucial determinant in the observed vibration transmissibility.

FAILURE MODE AND EFFECTS ANALYSIS (FMEA): INSTANT ERROR AND CONDITION MONITORING IN MANUFACTURING

Bu çalışmada, Endüstriyel mutfak ürünleri imal eden ve ürün gamında yüzlerce ana ürün ve binlerce yarı mamul bulunan bir firmanın talaşlı imalat atölyesinde Hata Türü ve Etkileri Analizi (HTEA) yöntemi uygulanmıştır. Atölyede bulunan, 12 adet makinaya yerleştirilen Programlanabilir Mantık Denetleyici (Programmable Logic Controller, PLC) kartlar ile anlık makinanın durumu, ürün ve üretim izlenmiştir. Makinelere yerleştirilen PLC kartları yardımıyla veriler merkezi bilgisayara kaydedilmiş olup, makinanın çalışmasıyla ilgili sağlıklı veriler elde edilmiştir. Çalışma kapsamında, Makineye yerleştirilen kartlardan alınan veriler ile makinelerin çalışma durumları, kapasite kullanım süreleri, makinelerin çalışma süreleri, sadece yatay torna makinelerine ait parça sıkılmış durumda bekleme süreleri, boşta bekleme süreleri, çalışma süreleri ve duruş süreleri elde edilmiştir. Operatörlere bağlı kalmadan elde edilen veriler doğrultusunda işletmede HTEA yöntemi uygulanmış olup, en çok karşılaşılan hata türleri belirlenerek 100’den büyük RÖS değerine sahip olanlar için önleyici ve düzeltici faaliyetler belirlenmiş ve uygulanmıştır. Ayrıca ana çalışmaya ek olarak talaşlı imalat firmalarının katlandığı en büyük maliyet kalemi olan kesici uç takımı maliyetleri de analiz edilmiş olup, HTEA uygulamasının yapılmadığı Ocak 2021 ile uygulamanın yapıldığı Şubat 2021 ve Mart 2021 üretim maliyetleri karşılaştırılmış ve değerlendirilmiştir.

A study on thermal displacement of CNC horizontal lathe based on movable component temperatures

ABSTRACT This paper presents a thermal error model for a lathe CNC machine using temperature on moving parts, which is usually a difficult measurement. Different working conditions are performed to obtain temperature and thermal displacement of the machine. A multi-linear regression model is applied for modelling relationship between temperatures and thermal errors. Data of two constant working conditions are implemented to find out the fitting function. Through analysis, it shows that thermal errors for X- and Z-axes can be estimated based on only four temperature points (T2, T3, T10 and T12 for the X-axis and T4, T6, T7 and T11 for the Z-axis). Results reveal that using movable part temperature data (T12), the average and maximum error in the predicted thermal displacement of the X-axis can be reduced about 1/3 and 2/5 compared to without using T12, while the movable temperature point on Z-Screw (T8) has a tiny effect on the average and maximum error of predicted thermal displacement of the Z-axis. Results herein can provide useful information to develop a thermal compensation for the CNC lathe machine.

Study on Heat Sources of Horizontal Lathe Machine by Using Inverse Method

Thermal has significantly effect on high speed machine tools. When temperature growing up, it often causes processing errors and further reduces product quality. This paper aims to investigate magnitude of heat sources and temperature distribution in a horizontal lathe based on inverse method. In present thermal model, there is not only consideration of spindle but also analyzing relative structures. Simulated and experimental temperatures are used as input data to predict heat sources and temperature field. Effects of speed, number measured points, measurement errors and measured distance on predicted results are analyzed. Results indicate that this inverse method can accurately estimate the heat sources based on two measured temperatures at front and rear outer rings. The trend of estimated heat sources is then compared to measured load rate. Results herein are useful information for designing horizontal lathe spindle and reducing thermal errors.

In-service machine tool remanufacturing: a sustainable resource-saving and high-valued recovery approach

With great changes in production requirements, in-service machine tools may be unable to meet new production requirements. Aiming for this problem, a sustainable resource-saving and high-valued recovery approach for in-service machine tools is proposed, which integrates remanufacturing and product-service systems (PSS). In-service machine tool remanufacturing is defined as a new remanufacturing model based on condition monitoring and diagnosis, which is different from traditional used machine tool remanufacturing and new machine tool manufacturing mentioned in the current literature. Procedure framework of in-service machine tool remanufacturing is proposed, including condition monitoring and diagnosis, matching analysis, remanufacturability evaluation and decision-making, identification of potential problems, individualized redesign, disassembly, cleaning, inspection and classification, performance improvement as well as reassembly and inspection. Combining the remanufacturing practice of an in-service heavy-duty horizontal lathe, the comprehensive resource-efficient benefits of in-service machine tool remanufacturing are illustrated. The results show that the proposed remanufacturing model can restore in-service machine tools to like-new or better performance and upgrade their functionality, with great economic and social benefits. For the implementation of this remanufacturing model, an in-depth analysis of the supporting technologies such as condition monitoring and diagnosis, decision-making analysis, etc., should be done in future research to guarantee the production capacities of in-service machine tools.

Weakness Ranking Method for Subsystems of Heavy-Duty Machine Tools Based on FMECA Information

Heavy-duty machine tools are composed of many subsystems with different functions, and their reliability is governed by the reliabilities of these subsystems. It is important to rank the weaknesses of subsystems and identify the weakest subsystem to optimize products and improve their reliabilities. However, traditional ranking methods based on failure mode effect and critical analysis (FMECA) does not consider the complex maintenance of products. Herein, a weakness ranking method for the subsystems of heavy-duty machine tools is proposed based on generalized FMECA information. In this method, eight reliability indexes, including maintainability and maintenance cost, are considered in the generalized FMECA information. Subsequently, the cognition best worst method is used to calculate the weight of each screened index, and the weaknesses of the subsystems are ranked using a technique for order preference by similarity to an ideal solution. Finally, based on the failure data collected from certain domestic heavy-duty horizontal lathes, the weakness ranking result of the subsystems is obtained to verify the effectiveness of the proposed method. An improved weakness ranking method that can comprehensively analyze and identify weak subsystems is proposed herein for designing and improving the reliability of complex electromechanical products.

Reliability optimization design of hydraulic system considering oil contamination

This paper presents a reliability optimization design method for a hydraulic system that considers oil contamination. The proposed method applies the quantitative relationship between oil contamination and system reliability to the reliability design of a hydraulic system, while considering the performance, layout, and other design factors. A global reliability model of the hydraulic system is constructed based on the oil contamination control model. Further studies aiming at an optimization design model of the hydraulic system is established where the cost is the objective function, reliability index, size and structure range, performance requirements are constraints, structure size and oil change period are design variables. For illustration, a case study on the reliability optimization design of the oil supply point branch of the static pressure bracket of a certain type of heavy CNC horizontal lathe is considered.

Lightweight heavy-duty CNC horizontal lathe based on particle damping materials

With the development of high-precision, high-speed, and green computer numerical controlled (CNC) machine tools, the advantages of lightweight versions of such tools are becoming increasingly obvious. Taking a ZN-XK2840 CNC lathe as an example, in this study a lightweight design method is proposed for CNC machine tools based on particle damping technology. The static performance of conventional CNC machine tools is analyzed using a finite element method, and the wall thickness is optimized. Then, the dynamic characteristics of conventional CNC machine tools, such as the modal characteristics and harmonic response, are analyzed. The particle damping technology can effectively reduce the vibration of the machine structure in the vibration transmission path. In this paper, the discrete element dynamic method is used for the finite element model of a lathe. Based on a traditional machine tool, the dynamic characteristics of the machine tool structure with a particle damper are analyzed. The lathe with a particle damper is manufactured according to the lightweight design. The acceleration and displacement amplitudes of lightweight machine tools are smaller than those of traditional machine tools. The third-order natural frequency of lightweight CNC machine bed is increased by about 28.49%, and the vibration amplitude of harmonic response is reduced by 3.38%. Compared with the similar machine tools used in industry, the light CNC lathe with particle damper reduces the weight by 50.8% on average.

Decision-making method of heavy-duty machine tool remanufacturing based on AHP-entropy weight and extension theory

Abstract Heavy-duty machine tools are mostly used in bottleneck processes of manufacturing companies, which have high value-added, high technical content, and large remanufacturing value. The various alternative solutions directly affect the implementation of heavy-duty machine tool remanufacturing as well as its benefits. However, there is currently no scientific and reasonable quantitative method to compare various options and determine the optimal solution. This paper aims to propose a decision-making method of heavy-duty machine tool remanufacturing based on the AHP-entropy weight and extension theory. Firstly, an evaluation criteria system of heavy-duty machine tool remanufacturing is established, covering economic criteria (including remanufacturing cost and remanufacturing time) and technical performance criteria (including accuracy, reliability, processing efficiency, processing range, and ergonomics). Secondly, the decision-making model is presented to determine the optimal alternative solution for heavy-duty machine tool remanufacturing based on extension theory, in which weight for each evaluation criterion is defined by a method of AHP-entropy weight. Finally, combined with the remanufacturing of a heavy-duty horizontal lathe, the proposed decision-making method is verified and analyzed. The results show that the alternative for heavy-duty machine tool remanufacturing determined by this method can obtain better comprehensive benefits and reduce the potential risk of remanufacturing for various stakeholders.

A Comparative Study on the Tribological Behavior of SAE-AISI 1055 Steel and Brass (CuZn39Pb2) a Pin on Disc Type of Contact

The paper assesses and compares the friction and wear behavior of SAE-AISI 1055 steel and brass (CuZn39Pb2) under dry sliding condition. The tribological behavior was investigated and compared by conducting two different experiments, the first experiment conducted on a CSM tribometer, and the second experiment was carried out on a test bench in horizontal lathe machine where device holder pin is fabricated and mounted on a test bench and a rotating disc, varying the normal load exert on the disc by the pin and the rotation speed of the disc. These tests consisted of measuring friction coefficient and wear loss of samples. Experiments are carried out in normal load 5-10 N, sliding speed 0.24-0.35 and 0.48 m/s. Variations of coefficient of friction during sliding at different initial surface roughness, normal load and sliding speed are investigated. Results show that the two alloys had different friction and wear behavior, for steel friction coefficient increase slowly with the increase of normal load and sliding speed. For brass friction coefficient decreases with the increase of normal load and sliding speed. On the other hand, it is also found that wear loss increase with sliding distance. Microscopic of worn surfaces for each alloy were carried out and compared.

Fault Diagnosis of Rotary Parts of a Heavy-Duty Horizontal Lathe Based on Wavelet Packet Transform and Support Vector Machine.

The spindle box is responsible for power transmission, supporting the rotating parts and ensuring the rotary accuracy of the workpiece in the heavy-duty machine tool. Its assembly quality is crucial to ensure the reliable power supply and stable operation of the machine tool in the process of large load and cutting force. Therefore, accurate diagnosis of assembly faults is of great significance for improving assembly efficiency and ensuring outgoing quality. In this paper, the common fault types and characteristics of the spindle box of heavy horizontal lathe are analyzed first, and original vibration signals of various fault types are collected. The wavelet packet is used to decompose the signal into different frequency bands and reconstruct the nodes in the frequency band where the characteristic frequency points are located. Then, the power spectrum analysis is carried out on the reconstructed signal, so that the fault features in the signal can be clearly expressed. The structure of the feature vector used for fault diagnosis is analyzed and the feature vector is extracted from the collected signals. Finally, the intelligent pattern recognition method based on support vector machine is used to classify the fault types. The results show that the method proposed in this paper can quickly and accurately judge the fault types.

Application and comparative analysis on three dimensional camera measurement system in full size inspection of batch production parts

Box-type parts are the basic parts of general machines, they assemble the shaft, sleeve, gear and other related parts of the machine into a whole, so as to maintain the correct mutual position accuracy between the parts. Their complex forming structure, large matching dimensions and high precision requirements directly affect the accuracy, performance and life of the machine. Aiming at the problems of large size and low efficiency of single piece inspection for box parts, this paper takes the spindle box of horizontal lathe as the research object, simulates through virtual testing platform, puts several parts of the same box parts in a certain order, determines the appropriate angle and shoots batch parts placement model in many directions, and adopts three-dimensional method. The camera measurement system detects the full size of the same batch of products and obtains the test results. On this basis, the traditional laser tracking measurement method is used to detect and compare the randomly selected single spindle box. The comparison results show that the three-dimensional camera measurement method can detect the forming accuracy of batch box parts well under the appropriate position and photographic angle, and the full-scale measurement error can be effectively controlled within the technical allowable range. This study provides a preliminary basis for the three-dimensional camera measurement technology in improving the efficiency and accuracy of full-scale measurement of batch box parts.

Pengukuran Kesilindrisan Hasil Proses Pemotongan Mesin Bubut Untuk Mengetahui Kemampuan Mesin Menghasilkan Suatu Produk

The ability of machine tools to produce a product of good quality is needed by the industrial industry that exists today. Industrial industries that use machine tools are not only industries that produce products in the form of a tool or machine, machine tools are also widely used by industries or institutions that serve machine repair and providers of skills training. The quality of the machine measured using the geometry of the workpiece resulting from the machining process can be in the form of roundness, cylindrecity, tapers and other geometric shapes. The use of machine tools that continue for several years can result in a decrease in the ability of the machine to produce a product. The use of a long horizontal doall lt13 lathe will produce a form of workpiece cylindricity that is not the same as the condition of the the new machine tools, therefore testing activities are carried out by cutting the machine and seeing what the cylindrical value of the specimen is capable of achieving . From the results of the testing that has been carried out on a horizontal lathe as many as eight units, the values of cylindrical difference are different for each machine. The highest value of cylindricity is produced by lathes with machine number 8 and the smallest cylindrical value produced by lathes with machine number 3. The greatest tolerance is achieved in the quality of IT (international tolerance) 11 tolerance and the lowest is achieved in IT tolerance quality 10.

Identyfikacja przyczyn pogorszenia stanu powierzchni obrabianej na tokarce kołowej

Operational problems often remain undetected until a machine is commissioned and first machining is attempted. Heavy-duty machines are a specific group of machine tools due to the character of their manufacturing process. As they are often manufactured as single units, which involves high production costs, there are no prototype versions built and no tests are performed on them. Therefore, before the machine is complete, computer simulation methods are often the only validation tools of a machine project at the stage of designing. The variety of applications and the individuality of production are the reasons for the lack of standards defining the rigidity and precision of the cutting process performed by heavy machine tools. In this case analysis, the authors are considering a heavy duty rail wheel lathe, in which some issues were found during its exploitation which make it impossible to achieve the required shape, dimensions and surface finish, while working at set parameters. This article presents a comprehensive approach to the identification of the form and frequency of a machine tool supporting structure’s self-vibrations and their potential sources in the case study of a horizontal lathe for railway wheelsets. The authors, drawing on the results of their long-standing research and their experience in the field of heavy machine tool design and testing, indicate self-excited vibrations as a key factor machine’s operational behaviour, which is rarely considered in this type of machines

A novel machining of multi irregular surface using improved noncircular turning method

The backplane processing is an important part of the manufacture of electronic communication equipment; the current processing of backplane surface, especially the rough machining, is still using milling; and the production efficiency is quite low. This paper presents a new method to turn with a cylinder for the rough machining of multi backplane surfaces, which is based on a conventional horizontal lathe and uses the improved method of noncircular machining. The performance requirements of fast tool servo (FTS) device and control model for the machining of noncircular surface are analyzed firstly; the position following control strategy is used instead of traditional position interpolation, according to the multi backplane surfaces machining technology and control strategy; and a novel algorithm, which is combined UG (Unigraphics NX) software surface fitting with cubic spline curve fitting of multi backplanes’ space, is proposed for computer-aided manufacturing (CAM) software design. Finally, the proposed processing method and CAM model algorithm are proved to be effective through the simulation and actual verifications, the products meet the processing requirements and the processing time of each piece is reduced from 8 to 2 min, and they also greatly improve the production automation and achieve energy saving and emission reduction.

Reliability analysis of complex multi-state system with common cause failure based on evidential networks

With the increasing complexity and size of modern advanced engineering systems, the traditional reliability theory cannot characterize and quantify the complex characteristics of complex systems, such as multi-state properties, epistemic uncertainties, common cause failures (CCFs). This paper focuses on the reliability analysis of complex multi-state system (MSS) with epistemic uncertainty and CCFs. Based on the Bayesian network (BN) method for reliability analysis of MSS, the Dempster-Shafer (DS) evidence theory is used to express the epistemic uncertainty in system through the state space reconstruction of MSS, and an uncertain state used to express the epistemic uncertainty is introduced in the new state space. The integration of evidence theory with BN which called evidential network (EN) is achieved by adapting and updating the conditional probability tables (CPTs) into conditional mass tables (CMTs). When multiple CCF groups (CCFGs) are considered in complex redundant system, a modified β factor parametric model is introduced to model the CCF in system. An EN method is proposed for the reliability analysis and evaluation of complex MSSs in this paper. The reliability analysis of servo feeding control system for CNC heavy-duty horizontal lathes (HDHLs) by this proposed method has shown that CCFs have considerable impact on system reliability. The presented method has high computational efficiency, and the computational accuracy is also verified.

Selection of a Solution When Using Axiomatic Design

Over the years, the importance of the creativity inclusively in the field of design activities was highlighted. In accordance with the opinions of certain researchers, the divergent thinking could contribute to the increase of creative processes efficiency. On the other hand, the axiomatic design method is considered as a method able to stimulate the technical creativity when the problem of designing a mechanical equipment is stated. To increase the efficiency of using the axiomatic design method, the possibility of selecting the most convenient solution among many available solutions could be discussed. The analysis revealed that there are many methods that could be applied in the process of optimum solution selection among many available solutions. In this paper, some aspects concerning the possibilities of using the method of analytic hierarchy process are analyzed, inclusively by considering a case study concerning a device for investigating the universal horizontal lathe rigidity. Afterwards, the first axiom from axiomatic design method was applied to define the selected solution for the approached device.

Fault tree analysis of feeding control system for computer numerical control heavy-duty horizontal lathes with multiple common cause failure groups

The lathes are basic machine tools for manufacturing cylindrical parts. In recent years, the DLseries computer numerical control (CNC) heavy-duty horizontal lathes (HDHLs) have been widely used in the transportation, energy and aviation industries. High availability of the CNC heavy-duty lathes is demanded to guarantee the efficiency and benefit of these manufacturing industries. As one of the key subsystems of the HDHLs, the feeding control system is studied in this paper on reliability modeling and reliability analysis. The fault tree analysis (FTA) method is used for reliability modelling of the feeding control system. Considering the multiple common cause failure groups (CCFGs) existing in the system, a modified beta factor parametric model is introduced to model the common cause failure (CCF) in system. The reliability of feeding control system is then obtained and the effect of CCF on the reliability of the whole system is studied as well.

Preventing chatter vibrations in heavy-duty turning operations in large horizontal lathes

Productivity and surface finish are typical user manufacturer requirements that are restrained by chatter vibrations sooner or later in every machining operation. Thus, manufacturers are interested in knowing, before building the machine, the dynamic behaviour of each machine structure with respect to another. Stability lobe graphs are the most reliable approach to analyse the dynamic performance. During heavy rough turning operations a model containing (a) several modes, or (b) modes with non-conventional (Cartesian) orientations is necessary. This work proposes two methods which are combined with multimode analysis to predict chatter in big horizontal lathes. First, a traditional single frequency model (SFM) is used. Secondly, the modern collocation method based on the Chebyshev polynomials (CCM) is alternatively studied. The models can be used to identify the machine design features limiting lathe productivity, as well as the threshold values for choosing good cutting parameters. The results have been compared with experimental tests in a horizontal turning centre. Besides the model and approach, this work offers real worthy values for big lathes, difficult to be got from literature.

Digital Rapid Modeling Design of Heavy-Duty Cutting Blade Based on Solidworks

Heavy machinery processing industry has its own disadvantages, that is, the large size and heavy weight of workpieces. Some of them may even weigh hundreds of tons. When processing horizontal lathe, the turning diameter of it can be as long as six meters and the vertical lathe can reach ten meters. Heavy duty cutting mainly concerns about how to improve the processing efficiency, enhance the equipment utilization and to reduce energy consumption. Therefore, this proposes a higher requirement to heavy cutting tool, especially the design of the blade is of great importance. Based on the analysis of heavy cutting blade’s structure, this dissertation uses the method of parametric design which is suitable for Solidworks, with the combination of OLE and COM technology. It also utilizes Visual Basic on the Solidworks platform for secondary development and design, and develops the fast digital modeling software design. The software can not only realize the rapid modeling of heavy cutting blade, but also shorten the design cycle and improve the efficiency of the cutting tool which benefited from the convenient design of the heavy blade, which has a significantly practical application value.