introduction The CNC machine tool is a device that processes the workpiece according to the pre-programmed machining program. The machining program not only ensures that the machined workpiece meets the requirements of the drawing, but also makes the function and performance of the CNC machine tool fully exerted as much as possible. Graphical simulation of the operation of the program to verify the correctness of the machining program is of great significance. Not only that, CNC machining simulation training has received more and more attention. This is because CNC machining requires operators to be familiar with CNC programming commands, CNC functions, and machine performance. These features of CNC machining determine the traditional Technical training methods are no longer sufficient. The so-called traditional technical training method refers to the way in which the operator first learns the technical theory and operating procedures, and then goes to the production site to conduct skill training in the way of the master with the apprentice. The main disadvantage of this method is that CNC machine tools are generally more expensive equipment, and do not allow students to open, stop and manufacture accidents arbitrarily. Therefore, the number of mobile phones will be less, which will make the trainees have more time to master the operation skills. In addition, the level of the master is uneven, and the quality of teaching is difficult to guarantee. Therefore, CNC machining simulation plays an important role in verifying the correctness of the machining program and training the operator. This paper takes a wide range of CNC boring and milling machines and machining centers as the research object, mainly discusses the use of object-oriented technology to analyze CNC machine tools, and establishes CNC machine tool object classes and simulation models. The CNC machine tool referred to in this paper is the general term for CNC boring and milling machine and machining center. 1 Object-Oriented Technology in Simulation Systems Object-oriented technology describes and processes objects in close proximity to the real world. Its data abstraction, inheritance and polymorphism mechanisms are particularly suitable for describing complex objects with intrinsic mechanisms, and thus have been widely used in various industries. 1.1 Object-Oriented Technology In object-oriented technology, objects with the same structure and processing mechanism are abstracted as classes, and objects are an instance of a class. Objects not only have states or attributes described by data, but also operations for changing the state of objects (in object-oriented, these operations are called methods), which combines data and operations. Therefore, objects can describe things at the same time. And two aspects of behavior. Different objects are completed by message passing, and the internal data operations of the object are not visible to the outside. This is called data encapsulation. The object-oriented object inheritance mechanism allows the properties of the parent class to be passed to the subclass through inheritance. This feature provides the possibility to describe objects in the objective world. Object inheritance is very useful for resolving resource sharing between objects to improve the reusability and extensibility of software. Reusability and extensibility are maintainable for software products. It has a great impact on the quality and productivity of newer products. In object-oriented technology, determining the derived relationship between objects is the key to establishing the whole system. The whole system often has only one or a few basic object base classes, and the others are derived classes of the base class. The derived relationship of object-oriented technology allows us to obtain a large number of off-the-shelf properties and methods directly from existing classes, and its polymorphic properties allow us to define properties and methods different from the base class in the derived class. 1.2 Object-Oriented Analysis of CNC Machine Tools Although the structure of CNC machine tools is complex, they are composed of relatively independent and relatively fixed modules with different functions. The object-oriented method is used to analyze CNC machine tools. The specific CNC machine tools and modules are regarded as objects, that is, CNC machine tools are mutually Independent of various objects, Figure 1 shows the object model of the CNC machine tool. In the object model, the CNC machine tool consists of a spindle, a column, a bed, a table, a control panel, a tool changer, and a pallet changer. It is slightly different from the actual simulation object composition. Some components not related to simulation, such as hydraulic system and electrical system, can be ignored in the simulation model to simplify the simulation model. The black sphere points "·" and "l å" in the figure are multiple symbols, indicating that many instances of one class are related to instances of another class, and the hollow sphere point "O" represents 0 or 1 instance of a class. An instance of another class. As can be seen from the object diagram, the main shaft, main column, bed, table, and control panel are the necessary components of each CNC machine tool. The tool changer and the pallet changer are optional components, but for the machining center. The tool changer and the pallet changer are also required components. 1.3 Inspection of exclusion relations CNC machine tools are not any combination of all components. The selection and matching between components has a certain exclusion relationship. The simulation system must be able to describe these exclusion relationships to ensure that the simulation model reflects the actual CNC machine tools. For example, in a tool changer, the robot is an optional part and the magazine is a required part, but once the chain magazine is selected, a robot must be selected; the machining center can have multiple magazines, but it must be with the robot The tool change can be completed. Similarly, the work table and the tray device also have an exclusive relationship. The rectangular table cannot be equipped with the tray device on the same CNC machine; the movement mode of the index table base determines the index table and The type of tray device type, the fixed work table of the base can only be selected with the rotary tray device, and so on. Since there are only exclusive relationships between components in the simulation system, and the number of component types is limited (but in each type, the component models are infinite), each component type can be given a certain ID number in advance. According to the standard of CNC machine tools, the number of types of CNC machine tools is small, and the simulation system can enumerate all the ID numbers of each CNC machine tool with exclusion relationship. The exclusion relationship is described by a set. Let A and B be two sets. a1, a2, ..., an represent the ID number of the CNC machine part, and are the elements in the set A. b1, b2, ..., bm also represent the ID of the CNC machine part. Number, which is the element of set B, ie A={a1, a2,...,an} B={b1,b2,...,bm} Then the exclusion relationship in the simulation system can be expressed as: set A rejects set B, or set B rejects the set A, that is, if a certain element of the set A and B exists in a certain simulation model, it means that there is component exclusion in the model, and the component type needs to be re-selected. Next page Handmade Apron Kitchen Sink,Kitchen Sink,Stainless Handmade Apron Farmhouse,Handmade Apron Farmhouse Kitchen Sink Guangdong Huayou Hardware Products Co.,Ltd , http://www.gudsink.com