CADCAM英文版期末复习资料.docx

一. What is CAD, CAPP, CAM and CIMS, and briefly describe the relationship between them.1.CAD: computer-aided design ,it mainly refers to the use of the computer to complete the entire process of product design generally including CAD design and analysis of two aspects.2, CAPP: Computer Aided Process Planning, it refers to the use of computer technology to complete process planning of part machining.3.CAM: computer-aided manufacturing, it refers to the use of computers and numerical control equipment (such as CNC machine tools, machining centers, etc.) to manufacture parts.4.CAD / CAM: computer-aided design and computer-aided manufacturing referred to using the computer as the primary means to generate and use a variety of digital information and graphical information for the design and manufacture of the product.5.The relationship between CAD, CAPP, CAM: Generally speaking, CAD / CAM CAD / CAPP / CAM of. Referred to that contained in the CAD / CAM systems have CAPP. CAD system to produce parts (including geometric information and process manufacturing information, such as tolerance requirements, surface roughness, etc.). CAPP system to accept information from CAD, and the use of reasonable design, process design knowledge processing, optimized processing parameters and processing equipment. CAM CAD / CAPP / CAM system to accept the part information from the CAD and CAPP process planning and process parameters, after the processing of the CAM system to generate NC code, incoming numerical control equipment control equipment automatically processed6.CAD / CAM technology trends: integrated, intelligent, standardization, network-based, three-dimensional二：CADCAM1: Fill in the blanks (the big issue 20 small problem, every empty 1.5 points, a total of 30 points)(1) FMS is the abbreviation of Flexible Manufacturing System.(2) APT is an automatic programming tool (Automatically Programmed Tool) .(3) CAM is the abbreviation of computer aided manufacturing.(4) IMS is an abbreviation of the Intelligent Manufacturing Systems (Intelligent Manufacturing System.(5) RPM Rapid Prototyping / parts manufacturing (Rapid Prototyping / Parts Manufacturing abbreviation.(6) AM agile manufacturing Agile Manufacturing of abbreviations.(7) CAD functions can be grouped into geometric model, the four categories of engineering analysis, dynamic simulation and automatic drawing.(8) the engineering database for input and output, and management is required in the design process of the data used and generated by the pattern, documents, etc.(9) usually refers only to the narrow CAM NC program preparation, including the regulation of the tool path, the cutter location file generated simulation of the tool path and NC code generation.(10) The development of application software based on the the User programming language (UPL) supporting and CAD / CAM software system integrally has a good user interface, such enhancements may extend the function of the CAD / CAM software system.(11) The application software can be automatic programming software, including identifying and processing of the source language software written by the CNC language (such as the APT language software) and a variety of CAD / CAM software.(12) to optimize the design including the optimization of the overall program the part structure optimization and optimization of process parameters.(13) CAD / CAM is a human-computer interaction process, from the shape of the products, ideas and programs, structural analysis process simulation system at any time to ensure the user to view, modify, intermediate results, real-time editing process.(14) modeling technique is the core of the CAM system, for the design and manufacture of the product to provide all the basic data and the original information, is the basis of the subsequent processing.(15) CAD / CAM system according to the three-dimensional model to calculate the geometric characteristics and physical characteristics of the corresponding objects.(16) CAD / CAM system with good information transmission management functions and information exchange process, to support the design and manufacture of the whole process of information transmission and exchange, and the transmission and sharing of information between multiple designers and design teams.(17) CIMS subsystem including management information systems, manufacturing automation systems and CAD / CAPP / CAM integrated system.(18) networking equipment necessary equipment, CAD / CAM systems set up its network equipment is composed of a computer network hubs, network cards, the transmission medium.(19) System software is responsible for managing hardware resources and software resources, for all users, it is a public computer software, including operating systems, compilers, graphics jack and jack standard.(20) Boolean operations, including pay and poor kinds of operations.2: Explain the following terms (the big issue of 6, a total of 18 points)(1) parametric modeling: parametric modeling is to first establish the constraint relationship between the graphics and size parameters, and then use constraints to define and modify the geometry model. Size constraints and topological constraints reflect the factors to be considered in the design. Because the parameters of a set of parameters to maintain a certain relationship with these constraints, the initial design of the entity is natural to meet these constraints, enter the new parameter values will also keep these constraints and get a new geometric model.(2) plane contour sweeping method: planar contour sweeping method is closely combined with a two-dimensional system, commonly used in a way prismatic or rotary generated. Planar contour scanning method is translated in space by any plane contour a distance or around a fixed axis of rotation of will scan an entity. The plane contour scanning of the prerequisites is to have a closed planar contour (ie the plane contour scanning voxel). Closed planar contour is moved along one coordinate direction or rotation around a given axis.(3) Forming manufacturing technology: molding manufacturing technology is casting, plastic processing, connection, a collection of techniques of powder metallurgy unit. Prototyping and manufacturing technologies are manufacturing the workpiece blank, close to the shape of the part to be made directly workpiece precision molding technology. Plastic molding and grinding combined will replace most of the small parts machining.(4) Boolean operators: Boolean operators is the basis of geometric modeling technology, it is a set operation from Boolean algebra. Boolean operations voxel can be combined into complex shapes, the two objects combined to construct a new object. Boolean operations can facilitate the construction of complex geometric entities. Therefore, in the geometric modeling Boolean operation is very important. Boolean operators include cross (intersection), and (Union) (Difference) three operations.(5) contour milling: the tool contour inspection hierarchical processing of the workpiece, the peripheral contour finishing choose a method.The milling part contour to be considered to maximize the use of the climb milling processing methods, this can increase the surface roughness of parts and machining accuracy and reduce the Machine flutter. To select reasonable into the retraction position, try to avoid along the part contour method to pause midway to cut and feed; into the retraction position is to be elected in a less important position; when the workpiece border open, in order to ensure processing surface quality, should be outside the boundaries of the workpiece into and retract.(6) virtual manufacturing: the virtual manufacturing is to achieve the essence of the actual manufacturing process on the computer, that computer simulation and virtual reality technology, group work together on the computer, product design, process planning, manufacturing, performance analysis, quality inspection and enterprise levels, process management and control products such as the nature of the manufacturing process in order to enhance the manufacturing process at all levels of decision-making and control.(7) modification technology: modification technology, including the technology of heat treatment and surface engineering. The major trends is achieved through a variety of new precision heat treatment and composite processing the accurate performance parts, precision of shapes and sizes and a variety of special performance requirements of the surface (coating), while significantly reducing energy consumption and completely eliminate the pollution of the environment.(8) placed characteristics: Place features include hole features, round features, chamfer feature array characteristics. Placing characterized in that the parametric feature to change the location of the feature size and shape parameters, characteristic shape can be changed. Placed generally characterized by late in Part modeling was gradually added, because these features are designed to supplement and refine Part, such as the premature join, will shape the inconvenience.(9) feature-based modeling: feature-based modeling is usually characterized by the shape model the accuracy feature model, material characteristics model, the shape of the feature model is the core and foundation of feature-based modeling. Is characterized by an integrated concept, as a carrier of information in the product development process, in addition to containing the part geometry and topology information, but also includes some non-geometric information required in the design and manufacturing process. Feature-based modeling is a built in solid modeling based on the use of the characteristics of the concept-oriented modeling method of the entire product design and manufacturing process design, it not only contains information related to the production, but also to describe the relationship between these information .(10) tool set sub-sequence method: Tool centralized sub-sequence method is used by the the tool division process, the site can be completed with the same knife finish machining parts, and then the second, third knife they can accomplish other parts. This can reduce the number of tool changes, compressed air-way time, reduce unnecessary positioning error.(11) geometric modeling: geometric modeling by geometric elements such as point, line, surface, body, after geometric transformations such as translation, rotation and cross, and poor Boolean operations, resulting in a solid model. Geometric modeling technology as the basis of the CAD / CAM technology, wide range of applications in the field of mechanical engineering.(12) characterized in tree: a feature-based modeling process, the characteristics of 11 successively added to the model, the follow-up characteristic feature attached to the front, the front characteristics of the changes will affect the follow-up characteristics of the changes. In order to properly record the course of feature-based modeling, the use of the feature tree concept, feature-based modeling process as a tree growing process, starting from the root (basic features), and gradually grow tree twigs (additional features). Part structure of different levels of complexity, the complexity of the feature tree type.Brief answer (the big 4, a total of 25 points)(1) CAD / CAM system (6)1. A variety of CAD / CAM systems basic human-computer interaction (also known as man-machine dialogue) (1)2. The operator according to the specific requirements of the instruction issued to the computer (1),3. Computer will be the result of the operation in the form of graphics or data displayed on the computer display (1)4. Operator via the input device to issue a new command to the computer (1).5. Computer according to the new instructions to complete the new instruction (1).6. The job information in the CAD / CAM generated continuously modify, exchange, access process. (2)(2) which aspects should pay attention to when the workpiece is being clampedShould maximize the use of modular fixture, but when the workpiece bulk, high precision, you can design special fixtures. (1)2 part positioning, clamping parts should be without prejudice to the measurement of the various parts of the processing, the replacement of the tool as well as important parts of the tool and the workpiece, tool and fixture collision phenomenon, in particular, should be avoided. (2)3 clamping force should seek close to the main points of support within the triangle formed by the points of support; should seek close to the cutting area, and rigid; Try not above the aperture processing, to reduce the warp. (2)4 parts clamping, positioning to consider the consistency of repeated installations, in order to reduce the time on the knife to improve the consistency of the same batch parts processing; generally the same batch of parts with the same positioning reference and the same clamping means. (2)(3) how to determine the point on the knife and tool change point (6)1. Knife point CNC machining starting point of the tool relative to the workpiece movement, the position of the tool in the workpiece coordinate system. (1)2. Determine the knife point of principle is: to facilitate the mathematical processing and simplify programming; easy alignment on the machine; to facilitate inspection process; processing errors caused by small. (2)3. Knife point can be set on the part fixture or machine, but must be part of the positioning reference coordinate dimensions, so as to determine the relationship between the machine coordinate system and workpiece coordinate system. (1)4. When you require a higher accuracy of the knife, the knife point should be selected on the part of the design basis or process basis. For parts positioning hole, the election center of the hole as the knife point. (1)5. Should be on the knife, the knife point coincide with the knife sites. Knife sites for end mills, end mill as the center of the underside of the head, the ball head center ball end mill for turning, boring tool is the tool tip for the drill bit to drill tip. (1)6. The tool change point should be determined according to the process content. In order to prevent the tool bumps workpiece is when the tool change, tool change point should be located in the outside of the part or fixture. (1)(4) the difference of the feature tree and the course number and contact (7)1. Feature tree and subsequent features characteristic attached to the front, the front characteristics of the changes will affect the follow-up characteristic changes. A complex parts by many characteristics, the characteristics of complex dependencies (2)2. Feature tree for parametric modeling system (2)3. History tree the variable modeling system using (2)4. Characteristics in addition to the history tree remain associated with the characteristics of the front, at the same time to establish contact with the system global coordinate system. The history tree also allows a number of parts merged together to construct a complex parts. The history tree clearly documented the design process, easy to modify, easy multiplayer co-design. (1)IV: Analysis answer the following questions (the big issue of small, a total of 27 points)(1) feature-based solid modeling method which is divided into several categories, its shape What are the steps (13)A modeling program planning: including the characteristics of the analysis part, the relationship between the analysis part features, the construction method of the analysis of the characteristics of the construction sequence and characteristics. (4)2 Create the basic characteristics of the basic features: the building blocks of a part. (3)3 to create additional features: add on additional features one by one according to the shape of program planning. (2)4 Edit to modify the characteristics of: any time in the process of feature-based modeling can be modified characteristics, including modifying the characteristics of the shape, size, location, or characterized by affiliation, or even delete constructed features. (3)5 generated drawings: 3D to 2D tec