Design Process Of Machine Tools Research Articles

Design and Simulation of CNC Milling Machine on Matlab

The development and revision of milling machines and components are continuous. With the help of computer technology, we can simulate some activities in a manufacturing system. The main purpose of a simulation is to understand and imitate the behavior of a particular manufacturing system on a computer, before hardware creation, thereby reducing the amount of testing and experimentation in the field. By using a virtual system, less material is wasted and the constraints on the actual operation of the machine in the field can be minimized. In the field of milling machinery, various modeling and simulation methods have been introduced so far. Today, the manufacture of a machine tool can no longer use the time-consuming and costly manufacturing and testing of physical prototypes to detect weak points and then optimize the design. In contrast, the current machine tool design process uses "virtual prototyping" technology to reduce the cost and time of hardware testing and iterative improvements to physical prototypes. The model of a milling machine can be simulated in Matlab simulations through analytical methods using various compositions. The presented virtual modeling methods and milling machine tool simulations make it possible to design, perform complex analyses, test, optimize, and use various types of control structures. in the computer simulation.
 Keywords: Milling Machine, CNC Miling Machine, Matlab

Research on green design framework and support system of metal cutting machine

In order to improve the green design level of metal cutting machine tools, the framework and implementation methods for enhancing the green performance of machine tool’s design process were studied. Analysing the environmental impact of design process, studying the green key points in the design process of materials, structures, hydraulics, lubrication and cooling, a green design framework for the metal cutting machine was established. Centering on the machine tool design process; Researching on the machine tool design support technology and implementation tools, a basic support system for green design of metal cutting machine that integrates technical support layer, interaction layer, tool support layer, technical support layer and user service layer was established. The green design support system for gear making machine was developed and applied to verify the guiding role of green framework and support system in the green design process of metal cutting machine tool.

Dynamic substructuring of machine tools considering local damping models

Dynamic substructuring is widely known and applied for different types of systems to divide a structure into subsystems while considering the dynamic influences of the coupled structure. For complex systems such as machine tools, substructuring becomes more difficult. Nevertheless, dividing a machine tool into substructures allows for a more efficient optimization of machine tool design regarding different machine positions. Recent substructuring approaches for machine tools focus on the modelling of mass and stiffness properties while lacking proper local damping models for each component. Damping is usually added after the coupling of the individual components by using measured or empirical values for the overall system in the current state. Therefore, a real prototype of the machine is needed to predict accurate results for the system behavior. This paper proposes a substructuring approach, which includes the local damping of each dissipation source on the substructure level. Each substructure is modelled using viscous and hysteretic damping models for the individual damping sources followed by a Craig-Bampton-reduction of the substructure. The reduced mass, stiffness and damping matrices are coupled in the desired machine position to predict the behavior of the machine tool structure. The hysteretic damping is thereby transformed using equivalent viscous damping values to allow for a simulation of the machine’s dynamic behavior in the time domain. The results of this substructure coupling approach are compared to a standard mode acceleration approach of the non-substructured machine tool, which needs to be recalculated for every machine position or design changes to individual components. Furthermore, the influence of the frequency range on the substructure reduction results is evaluated. It is shown, that the presented coupling approach is in high accordance with traditional reduction approaches. With this modelling approach, the dynamic behavior of a machine tool can be predicted at different machine positions without measuring the damping values on real prototypes or using simplified empirical values. This leads to new optimization possibilities in the design process of machine tools and thus to enhanced machine tool performance.

Rapid evaluation of machine tools with position-dependent milling stability based on response surface model

The milling stability is one of the important evaluation criterions of dynamic characteristics of machine tools, and it is of great importance for machine tools’ design and manufacturing. The milling stability of machine tools generally varies with the position combinations of moving parts. The traditional milling stability analysis of machine tools is based on some specific positions in the whole workspace of machine tools, and the results are not comprehensive. Furthermore, it is very time-consuming for operation and calculation to complete analysis of multiple positions. A new method to rapidly evaluate the stability of machine tools with position dependence is developed in this article. In this method, the key position combinations of moving parts are set as the samples of calculation to calculate the dynamic characteristics of machine tools with SAMCEF finite element simulation analysis software. Then the minimum critical axial cutting depth of each sample is obtained. The relationship between the position and the value of minimum critical axial cutting depth at any position in the whole workspace can be obtained through established response surface model. The precision of the response surface model is evaluated and the model could be used to rapidly evaluate the milling stability of machine tools with position dependence. With a precision horizontal machining center with box-in-box structure as an example, the value of minimum critical axial cutting depth at any position is shown. This method of rapid evaluation of machine tools with position-dependent stability avoids complicated theoretical calculation, so it can be easily adopted by engineers and technicians in the phase of design process of machine tools.

Hardware-in-the-Loop Machine Simulation for Modular Machine Tools

One of the most recognized trends in production today is the increasing demand of complex and personalized products. This leads to an increasing demand for machine tools. As a consequence machine tools are required to be adaptable and modifiable for different products or different conditions. To fulfill this precondition while keeping up or increasing productivity, the concept of modular systems is used nowadays to design and manufacture machine tools. However, during the first steps of planning new production processes neither the customer nor the manufacturer of a new machine tool knows the resulting effectiveness of the composed machine tool configuration. Currently assumptions on the effectiveness are made based on experience or comparative processes. This paper presentsa method for a hardware-in-the-loop machine simulation, which can be used to optimize the design process of machine tools based on modular systems. This machine simulation should automatically adjusts the virtual model according to the current machine tool configuration, taking into account 3D geometry, kinematic structure and its performance characteristics, e.g. acceleration and velocity. The specific configuration of the machine not only affects the virtual model but also the necessary configuration of the real CNC, which also influences the hardware-in-the-loop coupling needed for the simulation. Using a machine simulation with the developed methods will increase the quality of estimations during the first planning phases, thus improving the decision making process. Additionally, the communication between the manufacturer and the customer will be optimized by applying this method for sales and distribution. This paper describes first steps to create such a machine simulation, by combining and adapting numerous methods.

Analyses Using VR/AR Visualization

Aimed at improving the design process of machine tools using virtual reality (VR) and augmented reality (AR) systems, the Institute for Machine Tools and Production Processes (IWP) of Chemnitz University of Technology has developed new visualization methods for studying finite elements analysis (FEA) results in immersive environments along with a mobile AR system. The Institute's major goal on the software side was visualizing the direction and gradient of stress using 3D glyphs.

118 形状創成理論に基づく工作機械の加工誤差の解析(OS2 最新の工作機械(2))

Analysis of machining errors is very important in design process of machine tools. A kinematic model is proposed in the research to represent the motion errors between the tools and the workpieces. Two types of machining centers are considered in the research to analyze the machining errors due to the kinematic errors of the feed motions. The effects of the kinematic errors on the machining errors of the products are analyzed and compared by applying the model developed here.

Decision making by means of multi-dimensional evaluation vectors in basic layout design procedure. (Application to bearing selection and arrangement for machine tool spindle).

The design procedure generally consists of many processes, from concept design to the release of parts and assembly drawings. Over all these procedures, designers always analyse various design requirements and conduct the information processing so as to have the most suitable result. Consequently, to rationally automatise such a design procedure, it is necessary to effectively process the design and its related information, e. g., decision making, by the computer system. In this paper, therefore, to establish a future CAD system of artificial intelligence type, the decision making in the basic layout design process of machine tools has been investigated and a decision making method using the multi-dimensional evaluation vectors has been proposed. The validity of the proposed decision making method has also been verified through the development of a system for selecting the suitable bearing type and arrangement for the main spindle bearing system from many candidates.

Designer's Thinking Pattern in the Basic Layout Design Procedure of Machine Tools—Validity Evaluation of Thinking Block

To establish a future CAD system of artificial intelligence (AI) type, it is important and indispensable to adequately implant the thinking pattern of the mature designer in the computer environment. In this paper, therefore, the information flow within the basic layout design process of machine tools and also the thinking pattern, i.e., thinking way and decision making, of mature designers has been analysed, and the validity of the thinking block so far empirically employed has been investigated from the information processing point of view by using the cluster analysis.

Cutting Process Dynamics Simulation for Machine Tool Structure Design

A methodology to simulate the real cutting process dynamics using a finite element structural model and a mechanistic face milling force model is proposed. While the finite element structural model provides an analytic way to assess structural dynamic characteristics, the mechanistic face milling force model calculates the time histories of cutting forces taking many cutting process parameters into consideration and acts as forcing functions to the structural model. The methodology is verified through experimentation. The effects of structural parameters and cutting process parameters on the dynamic behavior of the machine tool structure are also studied. The results indicate that the proposed methodology can greatly enhance the machine tool design process.

Benchmark design process for machine tool structures

Traditionally the technical aspect of the machine tool design process has been handled by the more experienced veteran engineer. Although this is still largely true today, the power of the computer is changing many aspects of this design process. The veteran engineer's experience and knowledge of past and current products still puts him in a good position to coordinate the new design process. However, the computer has provided us with many added tools to incorporate into this process. These tools will supplement our experience, allow us to quantify it, and allow us to use knowledge of past products to predict performance of the new ones. Particularly in the areas of stress, statics, and machine tool dynamics such computerized methods as finite elements, system modeling, and modal analysis are proving themselves to be invaluable tools. With them the modern design team can achieve an understanding level of their new product never possible in the past. The best features of various designs can be selected, combined in the form of a prototype, and tested with the confidence that all the initial goals will be met.